iio: adc: lpc18xx_adc: Make use of the helper function dev_err_probe()

When possible use dev_err_probe help to properly deal with the
PROBE_DEFER error, the benefit is that DEFER issue will be logged
in the devices_deferred debugfs file.
Using dev_err_probe() can reduce code size, and the error value
gets printed.
Signed-off-by: Cai Huoqing <caihuoqing@baidu.com>
Link: https://lore.kernel.org/r/20211008092858.495-3-caihuoqing@baidu.comSigned-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/adc/lpc18xx_adc.c

@@ -153,19 +153,17 @@ static int lpc18xx_adc_probe(struct platform_device *pdev)
 		return PTR_ERR(adc->base);
 
 	adc->clk = devm_clk_get(&pdev->dev, NULL);
-	if (IS_ERR(adc->clk)) {
-		dev_err(&pdev->dev, "error getting clock\n");
-		return PTR_ERR(adc->clk);
-	}
+	if (IS_ERR(adc->clk))
+		return dev_err_probe(&pdev->dev, PTR_ERR(adc->clk),
+				     "error getting clock\n");
 
 	rate = clk_get_rate(adc->clk);
 	clkdiv = DIV_ROUND_UP(rate, LPC18XX_ADC_CLK_TARGET);
 
 	adc->vref = devm_regulator_get(&pdev->dev, "vref");
-	if (IS_ERR(adc->vref)) {
-		dev_err(&pdev->dev, "error getting regulator\n");
-		return PTR_ERR(adc->vref);
-	}
+	if (IS_ERR(adc->vref))
+		return dev_err_probe(&pdev->dev, PTR_ERR(adc->vref),
+				     "error getting regulator\n");
 
 	indio_dev->name = dev_name(&pdev->dev);
 	indio_dev->info = &lpc18xx_adc_info;