perf: Call perf_cgroup_event_time() directly

The perf_event_time() will call perf_cgroup_event_time()
if @event is a cgroup event. Just do it directly and avoid
the extra check..
Signed-off-by: NNamhyung Kim <namhyung.kim@lge.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Link: http://lkml.kernel.org/r/1327021966-27688-2-git-send-email-namhyung.kim@lge.comSigned-off-by: NIngo Molnar <mingo@elte.hu>

kernel/events/core.c

@@ -815,7 +815,7 @@ static void update_event_times(struct perf_event *event)
 	 * here.
 	 */
 	if (is_cgroup_event(event))
-		run_end = perf_event_time(event);
+		run_end = perf_cgroup_event_time(event);
 	else if (ctx->is_active)
 		run_end = ctx->time;
 	else