staging: bcm2835-audio: Kill unused spinlock

The alsa_stream->lock is never used.  Kill it.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Tested-by: Stefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/vc04_services/bcm2835-audio/bcm2835-pcm.c

@@ -128,8 +128,6 @@ static int snd_bcm2835_playback_open_generic(
 	alsa_stream->substream = substream;
 	alsa_stream->idx = idx;
 
-	spin_lock_init(&alsa_stream->lock);
-
 	err = bcm2835_audio_open(alsa_stream);
 	if (err) {
 		kfree(alsa_stream);

drivers/staging/vc04_services/bcm2835-audio/bcm2835.h

@@ -119,8 +119,6 @@ struct bcm2835_alsa_stream {
 	struct snd_pcm_substream *substream;
 	struct snd_pcm_indirect pcm_indirect;
 
-	spinlock_t lock;
-
 	int draining;
 
 	int channels;