sched/wait: Collapse __wait_event_interruptible_timeout()

Reduce macro complexity by using the new ___wait_event() helper.
No change in behaviour, identical generated code.

Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20131002092528.469616907@infradead.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

include/linux/wait.h

@@ -304,21 +304,9 @@ do {									\
 })
 
 #define __wait_event_interruptible_timeout(wq, condition, ret)		\
-do {									\
-	DEFINE_WAIT(__wait);						\
-									\
-	for (;;) {							\
-		prepare_to_wait(&wq, &__wait, TASK_INTERRUPTIBLE);	\
-		if (___wait_cond_timeout(condition, ret))		\
-			break;						\
-		if (signal_pending(current)) {				\
-			ret = -ERESTARTSYS;				\
-			break;						\
-		}							\
-		ret = schedule_timeout(ret);				\
-	}								\
-	finish_wait(&wq, &__wait);					\
-} while (0)
+	___wait_event(wq, ___wait_cond_timeout(condition, ret),		\
+		      TASK_INTERRUPTIBLE, 0, ret,			\
+		      ret = schedule_timeout(ret))
 
 /**
  * wait_event_interruptible_timeout - sleep until a condition gets true or a timeout elapses