Input: matrix_keypad - use flush_delayed_work()

We should be using flush_delayed_work() instead of flush_work() in
matrix_keypad_stop() to ensure that we are not missing work that is
scheduled but not yet put in the workqueue (i.e. its delay timer has not
expired yet).
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

drivers/input/keyboard/matrix_keypad.c

@@ -222,7 +222,7 @@ static void matrix_keypad_stop(struct input_dev *dev)
 	keypad->stopped = true;
 	spin_unlock_irq(&keypad->lock);
 
-	flush_work(&keypad->work.work);
+	flush_delayed_work(&keypad->work);
 	/*
 	 * matrix_keypad_scan() will leave IRQs enabled;
 	 * we should disable them now.