sched/wait: Deduplicate code with do-while

Statements in the loop's body and before it are identical.
Use do-while to not repeat it.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/43ffea6ee2152b90dedf962eac851609e4197218.1560256112.git.asml.silence@gmail.comSigned-off-by: Ingo Molnar <mingo@kernel.org>

kernel/sched/wait.c

@@ -118,16 +118,12 @@ static void __wake_up_common_lock(struct wait_queue_head *wq_head, unsigned int
 	bookmark.func = NULL;
 	INIT_LIST_HEAD(&bookmark.entry);
 
-	spin_lock_irqsave(&wq_head->lock, flags);
-	nr_exclusive = __wake_up_common(wq_head, mode, nr_exclusive, wake_flags, key, &bookmark);
-	spin_unlock_irqrestore(&wq_head->lock, flags);
-
-	while (bookmark.flags & WQ_FLAG_BOOKMARK) {
+	do {
 		spin_lock_irqsave(&wq_head->lock, flags);
 		nr_exclusive = __wake_up_common(wq_head, mode, nr_exclusive,
 						wake_flags, key, &bookmark);
 		spin_unlock_irqrestore(&wq_head->lock, flags);
-	}
+	} while (bookmark.flags & WQ_FLAG_BOOKMARK);
 }
 
 /**