V4L/DVB (4613): Unmute/mute saa7134 when opening/closing the audio capture device.

This patch should enable unmuting the audio device when opening it (and
posterior muting when closing it), doing away with the need for unmute ioctls
or v4lctl usage.
Signed-off-by: NRicardo Cerqueira <v4l@cerqueira.org>
Signed-off-by: NMauro Carvalho Chehab <mchehab@infradead.org>

drivers/media/video/saa7134/saa7134-alsa.c

@@ -590,6 +590,11 @@ static int snd_card_saa7134_hw_free(struct snd_pcm_substream * substream)
 
 static int snd_card_saa7134_capture_close(struct snd_pcm_substream * substream)
 {
+	snd_card_saa7134_t *saa7134 = snd_pcm_substream_chip(substream);
+	struct saa7134_dev *dev = saa7134->dev;
+
+	dev->ctl_mute = 1;
+	saa7134_tvaudio_setmute(dev);
 	return 0;
 }
 
@@ -631,6 +636,9 @@ static int snd_card_saa7134_capture_open(struct snd_pcm_substream * substream)
 	runtime->private_free = snd_card_saa7134_runtime_free;
 	runtime->hw = snd_card_saa7134_capture;
 
+	dev->ctl_mute = 0;
+	saa7134_tvaudio_setmute(dev);
+
 	if ((err = snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS)) < 0)
 		return err;