ALSA: isight: use position offset macro of TLV data

A series of SNDRV_CTL_TLVO_XXX macro was introduced for position offset
of TLV data. This commit applies a code optimization.
Signed-off-by: NTakashi Sakamoto <o-takashi@sakamocchi.jp>
Acked-by: NClemens Ladisch <clemens@ladisch.de>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

sound/firewire/isight.c

@@ -569,18 +569,20 @@ static int isight_create_mixer(struct isight *isight)
 		return err;
 	isight->gain_max = be32_to_cpu(value);
 
-	isight->gain_tlv[0] = SNDRV_CTL_TLVT_DB_MINMAX;
-	isight->gain_tlv[1] = 2 * sizeof(unsigned int);
+	isight->gain_tlv[SNDRV_CTL_TLVO_TYPE] = SNDRV_CTL_TLVT_DB_MINMAX;
+	isight->gain_tlv[SNDRV_CTL_TLVO_LEN] = 2 * sizeof(unsigned int);
 
 	err = reg_read(isight, REG_GAIN_DB_START, &value);
 	if (err < 0)
 		return err;
-	isight->gain_tlv[2] = (s32)be32_to_cpu(value) * 100;
+	isight->gain_tlv[SNDRV_CTL_TLVO_DB_MINMAX_MIN] =
+						(s32)be32_to_cpu(value) * 100;
 
 	err = reg_read(isight, REG_GAIN_DB_END, &value);
 	if (err < 0)
 		return err;
-	isight->gain_tlv[3] = (s32)be32_to_cpu(value) * 100;
+	isight->gain_tlv[SNDRV_CTL_TLVO_DB_MINMAX_MAX] =
+						(s32)be32_to_cpu(value) * 100;
 
 	ctl = snd_ctl_new1(&gain_control, isight);
 	if (ctl)