perf symbols: Do lazy symtab loading for the kernel & modules too

Just like we do with the other DSOs. This also simplifies the
kernel_maps setup process, now all that the tools need to do is
to call kernel_maps__init and the maps for the modules and
kernel will be created, then, later, when
kernel_maps__find_symbol() is used, it will also call
maps__find_symbol that already checks if the symtab was loaded,
loading it if needed.

Now if one does 'perf top --hide_kernel_symbols' we won't pay
the price of loading the (many) symbols in /proc/kallsyms or
vmlinux.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <1258757489-5978-4-git-send-email-acme@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c
index 0af4840..0d39e80 100644
--- a/tools/perf/builtin-report.c
+++ b/tools/perf/builtin-report.c
@@ -449,7 +449,7 @@
 		 * trick of looking in the whole kernel symbol list.
 		 */
 		if ((long long)ip < 0)
-			return kernel_maps__find_symbol(ip, mapp);
+			return kernel_maps__find_symbol(ip, mapp, NULL);
 	}
 	dump_printf(" ...... dso: %s\n",
 		    map ? map->dso->long_name : "<not found>");
@@ -496,7 +496,7 @@
 		case PERF_CONTEXT_HV:
 			break;
 		case PERF_CONTEXT_KERNEL:
-			sym = kernel_maps__find_symbol(ip, &map);
+			sym = kernel_maps__find_symbol(ip, &map, NULL);
 			break;
 		default:
 			sym = resolve_symbol(thread, &map, &ip);
@@ -716,7 +716,7 @@
 
 	if (cpumode == PERF_RECORD_MISC_KERNEL) {
 		level = 'k';
-		sym = kernel_maps__find_symbol(ip, &map);
+		sym = kernel_maps__find_symbol(ip, &map, NULL);
 		dump_printf(" ...... dso: %s\n",
 			    map ? map->dso->long_name : "<not found>");
 	} else if (cpumode == PERF_RECORD_MISC_USER) {