iio: adc: exynos_adc: Simplify with dev_err_probe()

Common pattern of handling deferred probe can be simplified with
dev_err_probe().  Less code and also it prints the error value.
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20200829064726.26268-4-krzk@kernel.orgSigned-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/adc/exynos_adc.c

@@ -844,13 +844,9 @@ static int exynos_adc_probe(struct platform_device *pdev)
 	}
 
 	info->vdd = devm_regulator_get(&pdev->dev, "vdd");
-	if (IS_ERR(info->vdd)) {
-		if (PTR_ERR(info->vdd) != -EPROBE_DEFER)
-			dev_err(&pdev->dev,
-				"failed getting regulator, err = %ld\n",
-				PTR_ERR(info->vdd));
-		return PTR_ERR(info->vdd);
-	}
+	if (IS_ERR(info->vdd))
+		return dev_err_probe(&pdev->dev, PTR_ERR(info->vdd),
+				     "failed getting regulator");
 
 	ret = regulator_enable(info->vdd);
 	if (ret)