iio: adc: rn5t618-adc: use devm_iio_map_array_register() function

This driver already hooks a similar unwind callback via
devm_add_action_or_reset().

They pretty much do the same thing, so this change converts it to the
devm_iio_map_array_register().
Signed-off-by: Alexandru Ardelean <aardelean@deviqon.com>
Reviewed-by: Andreas Kemnade <andreas@kemnade.info>
Link: https://lore.kernel.org/r/20210926162859.3567685-1-aardelean@deviqon.comSigned-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/adc/rn5t618-adc.c

@@ -197,13 +197,6 @@ static struct iio_map rn5t618_maps[] = {
 	{ /* sentinel */ }
 };
 
-static void unregister_map(void *data)
-{
-	struct iio_dev *iio_dev = (struct iio_dev *) data;
-
-	iio_map_array_unregister(iio_dev);
-}
-
 static int rn5t618_adc_probe(struct platform_device *pdev)
 {
 	int ret;
@@ -254,11 +247,7 @@ static int rn5t618_adc_probe(struct platform_device *pdev)
 		return ret;
 	}
 
-	ret = iio_map_array_register(iio_dev, rn5t618_maps);
-	if (ret < 0)
-		return ret;
-
-	ret = devm_add_action_or_reset(adc->dev, unregister_map, iio_dev);
+	ret = devm_iio_map_array_register(adc->dev, iio_dev, rn5t618_maps);
 	if (ret < 0)
 		return ret;