ALSA: jack: Use guard() for locking

We can simplify the code gracefully with new guard() macro and co for
automatic cleanup of locks.

Only the code refactoring, and no functional changes.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://lore.kernel.org/r/20240227085306.9764-11-tiwai@suse.de

sound/core/jack.c

@@ -42,11 +42,9 @@ static int snd_jack_dev_disconnect(struct snd_device *device)
 #ifdef CONFIG_SND_JACK_INPUT_DEV
 	struct snd_jack *jack = device->device_data;
 
-	mutex_lock(&jack->input_dev_lock);
-	if (!jack->input_dev) {
-		mutex_unlock(&jack->input_dev_lock);
+	guard(mutex)(&jack->input_dev_lock);
+	if (!jack->input_dev)
 		return 0;
-	}
 
 	/* If the input device is registered with the input subsystem
 	 * then we need to use a different deallocator. */
@@ -55,7 +53,6 @@ static int snd_jack_dev_disconnect(struct snd_device *device)
 	else
 		input_free_device(jack->input_dev);
 	jack->input_dev = NULL;
-	mutex_unlock(&jack->input_dev_lock);
 #endif /* CONFIG_SND_JACK_INPUT_DEV */
 	return 0;
 }
@@ -92,11 +89,9 @@ static int snd_jack_dev_register(struct snd_device *device)
 	snprintf(jack->name, sizeof(jack->name), "%s %s",
 		 card->shortname, jack->id);
 
-	mutex_lock(&jack->input_dev_lock);
-	if (!jack->input_dev) {
-		mutex_unlock(&jack->input_dev_lock);
+	guard(mutex)(&jack->input_dev_lock);
+	if (!jack->input_dev)
 		return 0;
-	}
 
 	jack->input_dev->name = jack->name;
 
@@ -121,7 +116,6 @@ static int snd_jack_dev_register(struct snd_device *device)
 	if (err == 0)
 		jack->registered = 1;
 
-	mutex_unlock(&jack->input_dev_lock);
 	return err;
 }
 #endif /* CONFIG_SND_JACK_INPUT_DEV */
@@ -586,14 +580,9 @@ EXPORT_SYMBOL(snd_jack_new);
 void snd_jack_set_parent(struct snd_jack *jack, struct device *parent)
 {
 	WARN_ON(jack->registered);
-	mutex_lock(&jack->input_dev_lock);
-	if (!jack->input_dev) {
-		mutex_unlock(&jack->input_dev_lock);
-		return;
-	}
-
-	jack->input_dev->dev.parent = parent;
-	mutex_unlock(&jack->input_dev_lock);
+	guard(mutex)(&jack->input_dev_lock);
+	if (jack->input_dev)
+		jack->input_dev->dev.parent = parent;
 }
 EXPORT_SYMBOL(snd_jack_set_parent);