ASoC: twl6040: Simplify custom put_volsw callback

Return -EINVAL in the unlikely event, if the function has been called
for unhandled control. This way we can remove one check in the code.
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

sound/soc/codecs/twl6040.c

@@ -759,15 +759,13 @@ static int twl6040_put_volsw(struct snd_kcontrol *kcontrol,
 		out = &twl6040_priv->handsfree;
 		break;
 	default:
-		break;
+		return -EINVAL;
 	}
 
-	if (out) {
 	out->left_vol = ucontrol->value.integer.value[0];
 	out->right_vol = ucontrol->value.integer.value[1];
 	if (!out->active)
 		return 1;
-	}
 
 	/* call the appropriate handler depending on the rreg */
 	if (mc->rreg)