ASoC: ti: davinci-evm: 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>
Acked-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Link: https://lore.kernel.org/r/20201029082513.28233-1-vulab@iscas.ac.cnSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/ti/davinci-evm.c

@@ -46,8 +46,7 @@ static void evm_shutdown(struct snd_pcm_substream *substream)
 	struct snd_soc_card_drvdata_davinci *drvdata =
 		snd_soc_card_get_drvdata(soc_card);
 
-	if (drvdata->mclk)
-		clk_disable_unprepare(drvdata->mclk);
+	clk_disable_unprepare(drvdata->mclk);
 }
 
 static int evm_hw_params(struct snd_pcm_substream *substream,