ALSA: usb-audio: unlock on error in probe

We need to unlock before we returning on this error path.

Fixes: 73ac9f5 ("ALSA: usb-audio: Add boot quirk for MOTU M Series")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/r/20200115174604.rhanfgy4j3uc65cx@kili.mountain
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/usb/card.c

@@ -602,7 +602,7 @@ static int usb_audio_probe(struct usb_interface *intf,
 	if (! chip) {
 		err = snd_usb_apply_boot_quirk_once(dev, intf, quirk, id);
 		if (err < 0)
-			return err;
+			goto __error;
 
 		/* it's a fresh one.
 		 * now look for an empty slot and create a new card instance