[ALSA] sound: virtuoso.c fix shadowed variable warning

Use priv_idx as an identifier.
sound/pci/oxygen/virtuoso.c:277:15: warning: symbol 'index' shadows an earlier one
sound/pci/oxygen/virtuoso.c:56:12: originally declared here

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/pci/oxygen/virtuoso.c

@@ -274,12 +274,12 @@ static void xonar_gpio_changed(struct oxygen *chip)
 
 static void mute_ac97_ctl(struct oxygen *chip, unsigned int control)
 {
-	unsigned int index = chip->controls[control]->private_value & 0xff;
+	unsigned int priv_idx = chip->controls[control]->private_value & 0xff;
 	u16 value;
 
-	value = oxygen_read_ac97(chip, 0, index);
+	value = oxygen_read_ac97(chip, 0, priv_idx);
 	if (!(value & 0x8000)) {
-		oxygen_write_ac97(chip, 0, index, value | 0x8000);
+		oxygen_write_ac97(chip, 0, priv_idx, value | 0x8000);
 		snd_ctl_notify(chip->card, SNDRV_CTL_EVENT_MASK_VALUE,
 			       &chip->controls[control]->id);
 	}