ALSA: bebob: change the range of critical section for stream data in PCM.hw_free callback

The operation of duplex streams should be in critical section.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/firewire/bebob/bebob_pcm.c

@@ -213,14 +213,15 @@ static int pcm_hw_free(struct snd_pcm_substream *substream)
 {
 	struct snd_bebob *bebob = substream->private_data;
 
-	if (substream->runtime->status->state != SNDRV_PCM_STATE_OPEN) {
 	mutex_lock(&bebob->mutex);
+
+	if (substream->runtime->status->state != SNDRV_PCM_STATE_OPEN)
 		bebob->substreams_counter--;
-		mutex_unlock(&bebob->mutex);
-	}
 
 	snd_bebob_stream_stop_duplex(bebob);
 
+	mutex_unlock(&bebob->mutex);
+
 	return snd_pcm_lib_free_vmalloc_buffer(substream);
 }