iio: dac: ad5446: Make ad5446_remove() return void

Up to now ad5446_remove() returns zero unconditionally. Make it return
void instead which makes it easier to see in the callers that there is
no error to handle.

Also the return value of i2c and spi remove callbacks is ignored anyway.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Alexandru Ardelean <ardeleanalex@gmail.com>
Link: https://lore.kernel.org/r/20211013203223.2694577-9-u.kleine-koenig@pengutronix.deSigned-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/dac/ad5446.c

@@ -283,7 +283,7 @@ static int ad5446_probe(struct device *dev, const char *name,
 	return ret;
 }
 
-static int ad5446_remove(struct device *dev)
+static void ad5446_remove(struct device *dev)
 {
 	struct iio_dev *indio_dev = dev_get_drvdata(dev);
 	struct ad5446_state *st = iio_priv(indio_dev);
@@ -291,8 +291,6 @@ static int ad5446_remove(struct device *dev)
 	iio_device_unregister(indio_dev);
 	if (!IS_ERR(st->reg))
 		regulator_disable(st->reg);
-
-	return 0;
 }
 
 #if IS_ENABLED(CONFIG_SPI_MASTER)
@@ -495,7 +493,9 @@ static int ad5446_spi_probe(struct spi_device *spi)
 
 static int ad5446_spi_remove(struct spi_device *spi)
 {
-	return ad5446_remove(&spi->dev);
+	ad5446_remove(&spi->dev);
+
+	return 0;
 }
 
 static struct spi_driver ad5446_spi_driver = {
@@ -572,7 +572,9 @@ static int ad5446_i2c_probe(struct i2c_client *i2c,
 
 static int ad5446_i2c_remove(struct i2c_client *i2c)
 {
-	return ad5446_remove(&i2c->dev);
+	ad5446_remove(&i2c->dev);
+
+	return 0;
 }
 
 static const struct i2c_device_id ad5446_i2c_ids[] = {