ASoC: tlv320aic31xx: Change aic31xx_power_off return type to void

The return value is not checked, and even if it was there is nothing
we could do about it and messages are already printed.
Signed-off-by: Andrew F. Davis <afd@ti.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/codecs/tlv320aic31xx.c

@@ -1081,16 +1081,13 @@ static int aic31xx_power_on(struct snd_soc_codec *codec)
 	return 0;
 }
 
-static int aic31xx_power_off(struct snd_soc_codec *codec)
+static void aic31xx_power_off(struct snd_soc_codec *codec)
 {
 	struct aic31xx_priv *aic31xx = snd_soc_codec_get_drvdata(codec);
-	int ret = 0;
 
 	regcache_cache_only(aic31xx->regmap, true);
-	ret = regulator_bulk_disable(ARRAY_SIZE(aic31xx->supplies),
-				     aic31xx->supplies);
-
-	return ret;
+	regulator_bulk_disable(ARRAY_SIZE(aic31xx->supplies),
+			       aic31xx->supplies);
 }
 
 static int aic31xx_set_bias_level(struct snd_soc_codec *codec,