ALSA: misc: Use guard() for spin locks

[ Upstream commit b8e1684 ]

Clean up the code using guard() for spin locks.

Merely code refactoring, and no behavior change.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://patch.msgid.link/20250829151335.7342-20-tiwai@suse.de
Stable-dep-of: 5337213 ("ALSA: core: Serialize deferred fasync state checks")
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: tiwai

sound/core/misc.c

@@ -202,35 +202,30 @@ int snd_fasync_helper(int fd, struct file *file, int on,
 		INIT_LIST_HEAD(&fasync->list);
 	}
 
-	spin_lock_irq(&snd_fasync_lock);
-	if (*fasyncp) {
-		kfree(fasync);
-		fasync = *fasyncp;
-	} else {
-		if (!fasync) {
-			spin_unlock_irq(&snd_fasync_lock);
-			return 0;
+	scoped_guard(spinlock_irq, &snd_fasync_lock) {
+		if (*fasyncp) {
+			kfree(fasync);
+			fasync = *fasyncp;
+		} else {
+			if (!fasync)
+				return 0;
+			*fasyncp = fasync;
 		}
-		*fasyncp = fasync;
+		fasync->on = on;
 	}
-	fasync->on = on;
-	spin_unlock_irq(&snd_fasync_lock);
 	return fasync_helper(fd, file, on, &fasync->fasync);
 }
 EXPORT_SYMBOL_GPL(snd_fasync_helper);
 
 void snd_kill_fasync(struct snd_fasync *fasync, int signal, int poll)
 {
-	unsigned long flags;
-
 	if (!fasync || !fasync->on)
 		return;
-	spin_lock_irqsave(&snd_fasync_lock, flags);
+	guard(spinlock_irqsave)(&snd_fasync_lock);
 	fasync->signal = signal;
 	fasync->poll = poll;
 	list_move(&fasync->list, &snd_fasync_list);
 	schedule_work(&snd_fasync_work);
-	spin_unlock_irqrestore(&snd_fasync_lock, flags);
 }
 EXPORT_SYMBOL_GPL(snd_kill_fasync);