ASoC: ssm2518: fix simple_return.cocci warnings

sound/soc/codecs/ssm2518.c:521:5-8: WARNING: end returns can be simpified

 Simplify a trivial if-return sequence.  Possibly combine with a
 preceding function call.
Generated by: scripts/coccinelle/misc/simple_return.cocci
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/codecs/ssm2518.c

@@ -518,10 +518,7 @@ static int ssm2518_set_bias_level(struct snd_soc_codec *codec,
 		break;
 	}
 
-	if (ret)
 	return ret;
-
-	return 0;
 }
 
 static int ssm2518_set_tdm_slot(struct snd_soc_dai *dai, unsigned int tx_mask,