ALSA: usb-audio: Don't avoid stopping the stream at disconnection

In the later patch, we're going to issue the PCM sync_stop calls at
disconnection.  But currently the USB-audio driver can't handle it
because it has a check of shutdown flag for stopping the URBs.  This
is basically superfluous (the stopping URBs are safe at disconnection
state), so let's drop the check.

Fixes: dc5eafe7 ("ALSA: usb-audio: Support PCM sync_stop")
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20210206203052.15606-4-tiwai@suse.deSigned-off-by: Takashi Iwai <tiwai@suse.de>

sound/usb/endpoint.c

@@ -890,9 +890,6 @@ static int stop_urbs(struct snd_usb_endpoint *ep, bool force)
 {
 	unsigned int i;
 
-	if (!force && atomic_read(&ep->chip->shutdown)) /* to be sure... */
-		return -EBADFD;
-
 	if (!force && atomic_read(&ep->running))
 		return -EBUSY;
 

sound/usb/pcm.c

@@ -270,10 +270,7 @@ static int snd_usb_pcm_sync_stop(struct snd_pcm_substream *substream)
 {
 	struct snd_usb_substream *subs = substream->runtime->private_data;
 
-	if (!snd_usb_lock_shutdown(subs->stream->chip)) {
-		sync_pending_stops(subs);
-		snd_usb_unlock_shutdown(subs->stream->chip);
-	}
+	sync_pending_stops(subs);
 	return 0;
 }