ALSA: au88x0 - Remove unused "Master Mono" Playback Volume and Playback Switch of ac97 codec

Remove "Master Mono Playback Volume" and "Master Mono Playback Switch"
of ac97 mixer since au88x0 does no use "Master Mono Pin" of AC97 codec
even au88x0 support mono playback
Signed-off-by: NRaymond Yau <superquad.vortex2@gmail.com>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

sound/pci/au88x0/au88x0_mixer.c

@@ -10,6 +10,15 @@
 #include <sound/core.h>
 #include "au88x0.h"
 
+static int remove_ctl(struct snd_card *card, const char *name)
+{
+	struct snd_ctl_elem_id id;
+	memset(&id, 0, sizeof(id));
+	strcpy(id.name, name);
+	id.iface = SNDRV_CTL_ELEM_IFACE_MIXER;
+	return snd_ctl_remove_id(card, &id);
+}
+
 static int __devinit snd_vortex_mixer(vortex_t * vortex)
 {
 	struct snd_ac97_bus *pbus;
@@ -28,5 +37,7 @@ static int __devinit snd_vortex_mixer(vortex_t * vortex)
 	ac97.scaps = AC97_SCAP_NO_SPDIF;
 	err = snd_ac97_mixer(pbus, &ac97, &vortex->codec);
 	vortex->isquad = ((vortex->codec == NULL) ?  0 : (vortex->codec->ext_id&0x80));
+	remove_ctl(vortex->card, "Master Mono Playback Volume");
+	remove_ctl(vortex->card, "Master Mono Playback Switch");
 	return err;
 }