ASoC: rt5682s: Use the devm_clk_get_optional() helper

Use devm_clk_get_optional() instead of hand writing it.
This saves some LoC and improves the semantic.
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/f538c24ad7b1926478347a03b5b7f0432e195e3b.1684594691.git.christophe.jaillet@wanadoo.frSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/codecs/rt5682s.c

@@ -2848,14 +2848,9 @@ static int rt5682s_dai_probe_clks(struct snd_soc_component *component)
 	int ret;
 
 	/* Check if MCLK provided */
-	rt5682s->mclk = devm_clk_get(component->dev, "mclk");
-	if (IS_ERR(rt5682s->mclk)) {
-		if (PTR_ERR(rt5682s->mclk) != -ENOENT) {
-			ret = PTR_ERR(rt5682s->mclk);
-			return ret;
-		}
-		rt5682s->mclk = NULL;
-	}
+	rt5682s->mclk = devm_clk_get_optional(component->dev, "mclk");
+	if (IS_ERR(rt5682s->mclk))
+		return PTR_ERR(rt5682s->mclk);
 
 	/* Register CCF DAI clock control */
 	ret = rt5682s_register_dai_clks(component);