staging: line6: Fix unlocked snd_pcm_stop() call

snd_pcm_stop() must be called in the PCM substream lock context.

Cc: <stable@vger.kernel.org>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

drivers/staging/line6/pcm.c

@@ -392,8 +392,11 @@ static int snd_line6_pcm_free(struct snd_device *device)
 */
 static void pcm_disconnect_substream(struct snd_pcm_substream *substream)
 {
-	if (substream->runtime && snd_pcm_running(substream))
+	if (substream->runtime && snd_pcm_running(substream)) {
+		snd_pcm_stream_lock_irq(substream);
 		snd_pcm_stop(substream, SNDRV_PCM_STATE_DISCONNECTED);
+		snd_pcm_stream_unlock_irq(substream);
+	}
 }
 
 /*