unwind: give all exported functions "unwind_" prefix

* unwind.c (init_unwind_addr_space): Rename to unwind_init.
(init_libunwind_ui): Rename to unwind_tcb_init.
(free_libunwind_ui): Rename to unwind_tcb_fin.
(delete_mmap_cache): Rename to unwind_cache_invalidate.
(print_stacktrace): Rename to unwind_print_stacktrace.
* defs.h: Update prototypes.
* mem.c: All callers updated.
* process.c: Likewise.
* strace.c: Likewise.
* syscall.c: Likewise.

Signed-off-by: Masatake YAMATO <yamato@redhat.com>
diff --git a/strace.c b/strace.c
index 0f7f16c..f8d5cb7 100644
--- a/strace.c
+++ b/strace.c
@@ -706,7 +706,7 @@
 
 #ifdef USE_LIBUNWIND
 			if (stack_trace_enabled)
-				init_libunwind_ui(tcp);
+				unwind_tcb_init(tcp);
 #endif
 
 			nprocs++;
@@ -747,7 +747,7 @@
 
 #ifdef USE_LIBUNWIND
 	if (stack_trace_enabled) {
-		free_libunwind_ui(tcp);
+		unwind_tcb_fin(tcp);
 	}
 #endif
 	memset(tcp, 0, sizeof(*tcp));
@@ -1818,7 +1818,7 @@
 
 #ifdef USE_LIBUNWIND
 	if (stack_trace_enabled)
-		init_unwind_addr_space();
+		unwind_init();
 #endif
 
 	if (!followfork)