iio:adc:ina2xx: Improve error reporting for problems during .remove()

Returning an error value in an i2c remove callback results in a generic
error message being emitted by the i2c core, but otherwise it doesn't
make a difference. The device goes away anyhow and the devm cleanups are
called.

So instead of triggering the generic i2c error message, emit a more
helpful message if a problem occurs and return 0 to suppress the generic
message.

This patch is a preparation for making i2c remove callbacks return void.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20220515155929.338656-2-u.kleine-koenig@pengutronix.deSigned-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/adc/ina2xx-adc.c

@@ -1038,12 +1038,18 @@ static int ina2xx_remove(struct i2c_client *client)
 {
 	struct iio_dev *indio_dev = i2c_get_clientdata(client);
 	struct ina2xx_chip_info *chip = iio_priv(indio_dev);
+	int ret;
 
 	iio_device_unregister(indio_dev);
 
 	/* Powerdown */
-	return regmap_update_bits(chip->regmap, INA2XX_CONFIG,
+	ret = regmap_update_bits(chip->regmap, INA2XX_CONFIG,
 				 INA2XX_MODE_MASK, 0);
+	if (ret)
+		dev_warn(&client->dev, "Failed to power down device (%pe)\n",
+			 ERR_PTR(ret));
+
+	return 0;
 }
 
 static const struct i2c_device_id ina2xx_id[] = {