staging: greybus: audio_helper: Use snd_ctl_remove_id()

Use the standard snd_ctl_remove_id() helper function instead of open
code. This allows us to reduce the manual card->rwsem lock in the
caller side.

Acked-by: Greg Kroah-Hartman <[e-mail]>
Cc: Johan Hovold <[e-mail]>
Cc: Alex Elder <[e-mail]>
Cc: [e-mail]
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Takashi Iwai <[e-mail]>

drivers/staging/greybus/audio_helper.c

···
 	for (i = 0; i < num_controls; i++) {
 		const struct snd_kcontrol_new *control = &controls[i];
 		struct snd_ctl_elem_id id;
-		struct snd_kcontrol *kctl;
 
 		if (prefix)
 			snprintf(id.name, sizeof(id.name), "%s %s", prefix,
···
 		id.device = control->device;
 		id.subdevice = control->subdevice;
 		id.index = control->index;
-		kctl = snd_ctl_find_id(card, &id);
-		if (!kctl) {
-			dev_err(dev, "Failed to find %s\n", control->name);
-			continue;
-		}
-		err = snd_ctl_remove(card, kctl);
-		if (err < 0) {
+		err = snd_ctl_remove_id(card, &id);
+		if (err < 0)
 			dev_err(dev, "%d: Failed to remove %s\n", err,
 				control->name);
-			continue;
-		}
 	}
 	return 0;
 }
···
 				      unsigned int num_controls)
 {
 	struct snd_card *card = component->card->snd_card;
-	int err;
 
-	down_write(&card->controls_rwsem);
-	err = gbaudio_remove_controls(card, component->dev, controls,
-				      num_controls, component->name_prefix);
-	up_write(&card->controls_rwsem);
-	return err;
+	return gbaudio_remove_controls(card, component->dev, controls,
+				       num_controls, component->name_prefix);
 }