iio: adc: max11100: Use devm_ functions for rest of probe()

By using devm_add_action_or_reset() to manage the regulator disable,
it becomes simple to use managed functions for all of remove.
This simplifies error handling and allows us to drop the remove()
function entirely.
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Jacopo Mondi <jacopo@jmondi.org>
Reviewed-by: Alexandru Ardelean <aardelean@deviqon.com>
Link: https://lore.kernel.org/r/20210516172520.1398835-3-jic23@kernel.org

drivers/iio/adc/max11100.c

@@ -102,6 +102,11 @@ static const struct iio_info max11100_info = {
 	.read_raw = max11100_read_raw,
 };
 
+static void max11100_regulator_disable(void *reg)
+{
+	regulator_disable(reg);
+}
+
 static int max11100_probe(struct spi_device *spi)
 {
 	int ret;
@@ -112,8 +117,6 @@ static int max11100_probe(struct spi_device *spi)
 	if (!indio_dev)
 		return -ENOMEM;
 
-	spi_set_drvdata(spi, indio_dev);
-
 	state = iio_priv(indio_dev);
 	state->spi = spi;
 
@@ -131,27 +134,12 @@ static int max11100_probe(struct spi_device *spi)
 	if (ret)
 		return ret;
 
-	ret = iio_device_register(indio_dev);
+	ret = devm_add_action_or_reset(&spi->dev, max11100_regulator_disable,
+				       state->vref_reg);
 	if (ret)
-		goto disable_regulator;
-
-	return 0;
-
-disable_regulator:
-	regulator_disable(state->vref_reg);
-
-	return ret;
-}
-
-static int max11100_remove(struct spi_device *spi)
-{
-	struct iio_dev *indio_dev = spi_get_drvdata(spi);
-	struct max11100_state *state = iio_priv(indio_dev);
-
-	iio_device_unregister(indio_dev);
-	regulator_disable(state->vref_reg);
+		return ret;
 
-	return 0;
+	return devm_iio_device_register(&spi->dev, indio_dev);
 }
 
 static const struct of_device_id max11100_ids[] = {
@@ -166,7 +154,6 @@ static struct spi_driver max11100_driver = {
 		.of_match_table = max11100_ids,
 	},
 	.probe		= max11100_probe,
-	.remove		= max11100_remove,
 };
 
 module_spi_driver(max11100_driver);