semaphore: use unlikely() for down's timeout

Signed-off-by: liguang <lig.fnst@cn.fujitsu.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/kernel/semaphore.c b/kernel/semaphore.c
index 4567fc0..9c7017d 100644
--- a/kernel/semaphore.c
+++ b/kernel/semaphore.c
@@ -214,7 +214,7 @@
 	for (;;) {
 		if (signal_pending_state(state, task))
 			goto interrupted;
-		if (timeout <= 0)
+		if (unlikely(timeout <= 0))
 			goto timed_out;
 		__set_task_state(task, state);
 		raw_spin_unlock_irq(&sem->lock);