Input: mt - convert locking to guard notation

Use guard() notation instead of explicitly acquiring and releasing
spinlocks to simplify the code and ensure that all locks are released.

Link: https://lore.kernel.org/r/20241107071538.195340-6-dmitry.torokhov@gmail.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Author: dtor

drivers/input/input-mt.c

@@ -285,14 +285,10 @@ void input_mt_drop_unused(struct input_dev *dev)
 	struct input_mt *mt = dev->mt;
 
 	if (mt) {
-		unsigned long flags;
-
-		spin_lock_irqsave(&dev->event_lock, flags);
+		guard(spinlock_irqsave)(&dev->event_lock);
 
 		__input_mt_drop_unused(dev, mt);
 		mt->frame++;
-
-		spin_unlock_irqrestore(&dev->event_lock, flags);
 	}
 }
 EXPORT_SYMBOL(input_mt_drop_unused);
@@ -339,11 +335,8 @@ void input_mt_sync_frame(struct input_dev *dev)
 		return;
 
 	if (mt->flags & INPUT_MT_DROP_UNUSED) {
-		unsigned long flags;
-
-		spin_lock_irqsave(&dev->event_lock, flags);
+		guard(spinlock_irqsave)(&dev->event_lock);
 		__input_mt_drop_unused(dev, mt);
-		spin_unlock_irqrestore(&dev->event_lock, flags);
 	}
 
 	if ((mt->flags & INPUT_MT_POINTER) && !(mt->flags & INPUT_MT_SEMI_MT))