perf symbols: Adopt the strlists for dso, comm

Will be used in perf diff too.

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: <1260914682-29652-2-git-send-email-acme@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/tools/perf/builtin-diff.c b/tools/perf/builtin-diff.c
index 67328d1..4fde606 100644
--- a/tools/perf/builtin-diff.c
+++ b/tools/perf/builtin-diff.c
@@ -265,11 +265,6 @@
 
 int cmd_diff(int argc, const char **argv, const char *prefix __used)
 {
-	if (symbol__init() < 0)
-		return -1;
-
-	setup_sorting(diff_usage, options);
-
 	argc = parse_options(argc, argv, options, diff_usage, 0);
 	if (argc) {
 		if (argc > 2)
@@ -281,6 +276,10 @@
 			input_new = argv[0];
 	}
 
+	if (symbol__init() < 0)
+		return -1;
+
+	setup_sorting(diff_usage, options);
 	setup_pager();
 	return __cmd_diff();
 }