ASoC: adau17x1: Remove redundant null check before clk_disable_unprepare

Because clk_disable_unprepare() already checked NULL clock parameter,
so the additional check is unnecessary, just remove it.
Signed-off-by: Xu Wang <vulab@iscas.ac.cn>
Link: https://lore.kernel.org/r/20210108084456.6603-1-vulab@iscas.ac.cnSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/codecs/adau17x1.c

@@ -1095,8 +1095,7 @@ void adau17x1_remove(struct device *dev)
 {
 	struct adau *adau = dev_get_drvdata(dev);
 
-	if (adau->mclk)
-		clk_disable_unprepare(adau->mclk);
+	clk_disable_unprepare(adau->mclk);
 }
 EXPORT_SYMBOL_GPL(adau17x1_remove);