perf_counter tools: Uniform help printouts

Also add perf list to command-list.txt.

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/Documentation/perf_counter/util/usage.c b/Documentation/perf_counter/util/usage.c
index 7a10421..2cad286 100644
--- a/Documentation/perf_counter/util/usage.c
+++ b/Documentation/perf_counter/util/usage.c
@@ -14,7 +14,7 @@
 
 static NORETURN void usage_builtin(const char *err)
 {
-	fprintf(stderr, "usage: %s\n", err);
+	fprintf(stderr, "\n usage: %s\n", err);
 	exit(129);
 }