iio: adc: stm32-adc: Remove redundant null check before clk_prepare_enable/clk_disable_unprepare

Because 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>
Acked-by: Fabrice Gasnier <fabrice.gasnier@foss.st.com>
Link: https://lore.kernel.org/r/20201218093512.871-1-vulab@iscas.ac.cnSigned-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/adc/stm32-adc-core.c

@@ -535,28 +535,23 @@ static int stm32_adc_core_hw_start(struct device *dev)
 		goto err_switches_dis;
 	}
 
-	if (priv->bclk) {
 	ret = clk_prepare_enable(priv->bclk);
 	if (ret < 0) {
 		dev_err(dev, "bus clk enable failed\n");
 		goto err_regulator_disable;
 	}
-	}
 
-	if (priv->aclk) {
 	ret = clk_prepare_enable(priv->aclk);
 	if (ret < 0) {
 		dev_err(dev, "adc clk enable failed\n");
 		goto err_bclk_disable;
 	}
-	}
 
 	writel_relaxed(priv->ccr_bak, priv->common.base + priv->cfg->regs->ccr);
 
 	return 0;
 
 err_bclk_disable:
-	if (priv->bclk)
 	clk_disable_unprepare(priv->bclk);
 err_regulator_disable:
 	regulator_disable(priv->vref);
@@ -575,9 +570,7 @@ static void stm32_adc_core_hw_stop(struct device *dev)
 
 	/* Backup CCR that may be lost (depends on power state to achieve) */
 	priv->ccr_bak = readl_relaxed(priv->common.base + priv->cfg->regs->ccr);
-	if (priv->aclk)
 	clk_disable_unprepare(priv->aclk);
-	if (priv->bclk)
 	clk_disable_unprepare(priv->bclk);
 	regulator_disable(priv->vref);
 	stm32_adc_core_switches_supply_dis(priv);

drivers/iio/adc/stm32-adc.c

@@ -546,7 +546,6 @@ static int stm32_adc_hw_stop(struct device *dev)
 	if (adc->cfg->unprepare)
 		adc->cfg->unprepare(indio_dev);
 
-	if (adc->clk)
 	clk_disable_unprepare(adc->clk);
 
 	return 0;
@@ -558,11 +557,9 @@ static int stm32_adc_hw_start(struct device *dev)
 	struct stm32_adc *adc = iio_priv(indio_dev);
 	int ret;
 
-	if (adc->clk) {
 	ret = clk_prepare_enable(adc->clk);
 	if (ret)
 		return ret;
-	}
 
 	stm32_adc_set_res(adc);
 
@@ -575,7 +572,6 @@ static int stm32_adc_hw_start(struct device *dev)
 	return 0;
 
 err_clk_dis:
-	if (adc->clk)
 	clk_disable_unprepare(adc->clk);
 
 	return ret;