iio: adc: twl4030: Return an error if we can not enable the vusb3v1 regulator...

iio: adc: twl4030: Return an error if we can not enable the vusb3v1 regulator in 'twl4030_madc_probe()'

If we can not enable the regulator, go through the error handling path
instead of silently continuing.

Fixes: 7cc97d77 ("iio: adc: twl4030: Fix ADC[3:6] readings")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/adc/twl4030-madc.c

@@ -893,8 +893,10 @@ static int twl4030_madc_probe(struct platform_device *pdev)
 	}
 
 	ret = regulator_enable(madc->usb3v1);
-	if (ret)
+	if (ret) {
 		dev_err(madc->dev, "could not enable 3v1 bias regulator\n");
+		goto err_i2c;
+	}
 
 	ret = iio_device_register(iio_dev);
 	if (ret) {