ASoC: pxa: pxa-ssp: Remove redundant null check before clk_prepare_enable/clk_disable_unprepare

ecause clk_prepare_enable() and clk_disable_unprepare() already checked
NULL clock parameter, so the additional checks are unnecessary, just
remove them.
Signed-off-by: Xu Wang <vulab@iscas.ac.cn>
Link: https://lore.kernel.org/r/20201029090104.29552-1-vulab@iscas.ac.cnSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/pxa/pxa-ssp.c

@@ -99,8 +99,7 @@ static int pxa_ssp_startup(struct snd_pcm_substream *substream,
 		pxa_ssp_disable(ssp);
 	}
 
-	if (priv->extclk)
-		clk_prepare_enable(priv->extclk);
+	clk_prepare_enable(priv->extclk);
 
 	dma = kzalloc(sizeof(struct snd_dmaengine_dai_dma_data), GFP_KERNEL);
 	if (!dma)
@@ -124,8 +123,7 @@ static void pxa_ssp_shutdown(struct snd_pcm_substream *substream,
 		clk_disable_unprepare(ssp->clk);
 	}
 
-	if (priv->extclk)
-		clk_disable_unprepare(priv->extclk);
+	clk_disable_unprepare(priv->extclk);
 
 	kfree(snd_soc_dai_get_dma_data(cpu_dai, substream));
 	snd_soc_dai_set_dma_data(cpu_dai, substream, NULL);