iio: adc: max1241: 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/20211008092858.495-5-caihuoqing@baidu.comSigned-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/adc/max1241.c

@@ -148,10 +148,9 @@ static int max1241_probe(struct spi_device *spi)
 	mutex_init(&adc->lock);
 
 	adc->vdd = devm_regulator_get(dev, "vdd");
-	if (IS_ERR(adc->vdd)) {
-		dev_err(dev, "failed to get vdd regulator\n");
-		return PTR_ERR(adc->vdd);
-	}
+	if (IS_ERR(adc->vdd))
+		return dev_err_probe(dev, PTR_ERR(adc->vdd),
+				     "failed to get vdd regulator\n");
 
 	ret = regulator_enable(adc->vdd);
 	if (ret)
@@ -164,10 +163,9 @@ static int max1241_probe(struct spi_device *spi)
 	}
 
 	adc->vref = devm_regulator_get(dev, "vref");
-	if (IS_ERR(adc->vref)) {
-		dev_err(dev, "failed to get vref regulator\n");
-		return PTR_ERR(adc->vref);
-	}
+	if (IS_ERR(adc->vref))
+		return dev_err_probe(dev, PTR_ERR(adc->vref),
+				     "failed to get vref regulator\n");
 
 	ret = regulator_enable(adc->vref);
 	if (ret)
@@ -182,7 +180,8 @@ static int max1241_probe(struct spi_device *spi)
 	adc->shutdown = devm_gpiod_get_optional(dev, "shutdown",
 						GPIOD_OUT_HIGH);
 	if (IS_ERR(adc->shutdown))
-		return PTR_ERR(adc->shutdown);
+		return dev_err_probe(dev, PTR_ERR(adc->shutdown),
+				     "cannot get shutdown gpio\n");
 
 	if (adc->shutdown)
 		dev_dbg(dev, "shutdown pin passed, low-power mode enabled");