iio:adc:ad7476: Fix remove handling

This driver was in an odd half way state between devm based cleanup
and manual cleanup (most of which was missing).
I would guess something went wrong with a rebase or similar.
Anyhow, this basically finishes the job as a precursor to improving
the regulator handling.

Signed-off-by: Jonathan Cameron <[e-mail]>
Fixes: 4bb2b8f94ace3 ("iio: adc: ad7476: implement devm_add_action_or_reset")
Cc: Michael Hennerich <[e-mail]>
Reviewed-by: Alexandru Ardelean <[e-mail]>
Cc: <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]

drivers/iio/adc/ad7476.c

···
 	spi_message_init(&st->msg);
 	spi_message_add_tail(&st->xfer, &st->msg);
 
-	ret = iio_triggered_buffer_setup(indio_dev, NULL,
-			&ad7476_trigger_handler, NULL);
+	ret = devm_iio_triggered_buffer_setup(&spi->dev, indio_dev, NULL,
+					      &ad7476_trigger_handler, NULL);
 	if (ret)
-		goto error_disable_reg;
+		return ret;
 
 	if (st->chip_info->reset)
 		st->chip_info->reset(st);
 
-	ret = iio_device_register(indio_dev);
-	if (ret)
-		goto error_ring_unregister;
-	return 0;
-
-error_ring_unregister:
-	iio_triggered_buffer_cleanup(indio_dev);
-error_disable_reg:
-	regulator_disable(st->reg);
-
-	return ret;
+	return devm_iio_device_register(&spi->dev, indio_dev);
 }
 
 static const struct spi_device_id ad7476_id[] = {