iio: adc: ltc2497: 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/20200829064726.26268-5-krzk@kernel.orgSigned-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/adc/ltc2497-core.c

@@ -180,13 +180,9 @@ int ltc2497core_probe(struct device *dev, struct iio_dev *indio_dev)
 		return ret;
 
 	ddata->ref = devm_regulator_get(dev, "vref");
-	if (IS_ERR(ddata->ref)) {
-		if (PTR_ERR(ddata->ref) != -EPROBE_DEFER)
-			dev_err(dev, "Failed to get vref regulator: %pe\n",
-				ddata->ref);
-
-		return PTR_ERR(ddata->ref);
-	}
+	if (IS_ERR(ddata->ref))
+		return dev_err_probe(dev, PTR_ERR(ddata->ref),
+				     "Failed to get vref regulator\n");
 
 	ret = regulator_enable(ddata->ref);
 	if (ret < 0) {