memleak: Migrate to new symbols resolution API

Remove usyms.py dependency and replace with new symbols API.
diff --git a/tools/memleak_example.txt b/tools/memleak_example.txt
index 5b6f8d4..accc74f 100644
--- a/tools/memleak_example.txt
+++ b/tools/memleak_example.txt
@@ -10,13 +10,13 @@
 Attaching to malloc and free in pid 5193, Ctrl+C to quit.
 [11:16:33] Top 2 stacks with outstanding allocations:
         80 bytes in 5 allocations from stack
-                 main+0x6d [/home/vagrant/allocs] (400862) 
-                 __libc_start_main+0xf0 [/usr/lib64/libc-2.21.so] (7fd460ac2790) 
+                 main+0x6d [allocs]
+                 __libc_start_main+0xf0 [libc-2.21.so]
 
 [11:16:34] Top 2 stacks with outstanding allocations:
         160 bytes in 10 allocations from stack
-                 main+0x6d [/home/vagrant/allocs] (400862) 
-                 __libc_start_main+0xf0 [/usr/lib64/libc-2.21.so] (7fd460ac2790) 
+                 main+0x6d [allocs]
+                 __libc_start_main+0xf0 [libc-2.21.so]
 
 
 Each entry printed is a set of allocations that originate from the same call
@@ -40,8 +40,8 @@
         addr = 948d30 size = 16
         addr = 948cf0 size = 16
         64 bytes in 4 allocations from stack
-                 main+0x6d [/home/vagrant/allocs] (400862) 
-                 __libc_start_main+0xf0 [/usr/lib64/libc-2.21.so] (7fd460ac2790) 
+                 main+0x6d [allocs]
+                 __libc_start_main+0xf0 [libc-2.21.so]
 
 [11:16:34] Top 2 stacks with outstanding allocations:
         addr = 948d50 size = 16
@@ -55,8 +55,8 @@
         addr = 948d70 size = 16
         addr = 948df0 size = 16
         160 bytes in 10 allocations from stack
-                 main+0x6d [/home/vagrant/allocs] (400862) 
-                 __libc_start_main+0xf0 [/usr/lib64/libc-2.21.so] (7fd460ac2790) 
+                 main+0x6d [allocs]
+                 __libc_start_main+0xf0 [libc-2.21.so]
 
 
 When using the -p switch, memleak traces the allocations of a particular
@@ -67,35 +67,35 @@
 Attaching to kmalloc and kfree, Ctrl+C to quit.
 ...
         248 bytes in 4 allocations from stack
-                 bpf_prog_load [kernel] (ffffffff8118c471) 
-                 sys_bpf [kernel] (ffffffff8118c8b5) 
+                 bpf_prog_load [kernel]
+                 sys_bpf [kernel]
 
         328 bytes in 1 allocations from stack
-                 perf_mmap [kernel] (ffffffff811990fd) 
-                 mmap_region [kernel] (ffffffff811df5d4) 
-                 do_mmap [kernel] (ffffffff811dfb83) 
-                 vm_mmap_pgoff [kernel] (ffffffff811c494f) 
-                 sys_mmap_pgoff [kernel] (ffffffff811ddf02) 
-                 sys_mmap [kernel] (ffffffff8101b0ab) 
+                 perf_mmap [kernel]
+                 mmap_region [kernel]
+                 do_mmap [kernel]
+                 vm_mmap_pgoff [kernel]
+                 sys_mmap_pgoff [kernel]
+                 sys_mmap [kernel]
 
         464 bytes in 1 allocations from stack
-                 traceprobe_command [kernel] (ffffffff81187cf2) 
-                 traceprobe_probes_write [kernel] (ffffffff81187d86) 
-                 probes_write [kernel] (ffffffff81181580) 
-                 __vfs_write [kernel] (ffffffff812237b7) 
-                 vfs_write [kernel] (ffffffff81223ec6) 
-                 sys_write [kernel] (ffffffff81224b85) 
-                 entry_SYSCALL_64_fastpath [kernel] (ffffffff8178182e) 
+                 traceprobe_command [kernel]
+                 traceprobe_probes_write [kernel]
+                 probes_write [kernel]
+                 __vfs_write [kernel]
+                 vfs_write [kernel]
+                 sys_write [kernel]
+                 entry_SYSCALL_64_fastpath [kernel]
 
         8192 bytes in 1 allocations from stack
-                 alloc_and_copy_ftrace_hash.constprop.59 [kernel] (ffffffff8115d17e) 
-                 ftrace_set_hash [kernel] (ffffffff8115e767) 
-                 ftrace_set_filter_ip [kernel] (ffffffff8115e9a8) 
-                 arm_kprobe [kernel] (ffffffff81148600) 
-                 enable_kprobe [kernel] (ffffffff811486f6) 
-                 kprobe_register [kernel] (ffffffff81182399) 
-                 perf_trace_init [kernel] (ffffffff8117c4e0) 
-                 perf_tp_event_init [kernel] (ffffffff81192479) 
+                 alloc_and_copy_ftrace_hash.constprop.59 [kernel]
+                 ftrace_set_hash [kernel]
+                 ftrace_set_filter_ip [kernel]
+                 arm_kprobe [kernel]
+                 enable_kprobe [kernel]
+                 kprobe_register [kernel]
+                 perf_trace_init [kernel]
+                 perf_tp_event_init [kernel]
 
 
 Here you can see that arming the kprobe to which our eBPF program is attached
@@ -129,18 +129,18 @@
 Attaching to malloc and free in pid 2614, Ctrl+C to quit.
 [11:16:33] Top 2 stacks with outstanding allocations:
         16 bytes in 1 allocations from stack
-                 main+0x6d [/home/vagrant/allocs] (400862) 
-                 __libc_start_main+0xf0 [/usr/lib64/libc-2.21.so] (7fdc11ce8790) 
+                 main+0x6d [allocs]
+                 __libc_start_main+0xf0 [libc-2.21.so]
 
 [11:16:38] Top 2 stacks with outstanding allocations:
         16 bytes in 1 allocations from stack
-                 main+0x6d [/home/vagrant/allocs] (400862) 
-                 __libc_start_main+0xf0 [/usr/lib64/libc-2.21.so] (7fdc11ce8790) 
+                 main+0x6d [allocs]
+                 __libc_start_main+0xf0 [libc-2.21.so]
 
 [11:16:43] Top 2 stacks with outstanding allocations:
         32 bytes in 2 allocations from stack
-                 main+0x6d [/home/vagrant/allocs] (400862) 
-                 __libc_start_main+0xf0 [/usr/lib64/libc-2.21.so] (7fdc11ce8790) 
+                 main+0x6d [allocs]
+                 __libc_start_main+0xf0 [libc-2.21.so]
 
 Note that even though the application leaks 16 bytes of memory every second, 
 the report (printed every 5 seconds) doesn't "see" all the allocations because