mfd: rt4831: 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>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20220502191012.53259-1-u.kleine-koenig@pengutronix.de

drivers/mfd/rt4831.c

@@ -90,9 +90,14 @@ static int rt4831_probe(struct i2c_client *client)
 static int rt4831_remove(struct i2c_client *client)
 {
 	struct regmap *regmap = dev_get_regmap(&client->dev, NULL);
+	int ret;
 
 	/* Disable WLED and DSV outputs */
-	return regmap_update_bits(regmap, RT4831_REG_ENABLE, RT4831_RESET_MASK, RT4831_RESET_MASK);
+	ret = regmap_update_bits(regmap, RT4831_REG_ENABLE, RT4831_RESET_MASK, RT4831_RESET_MASK);
+	if (ret)
+		dev_warn(&client->dev, "Failed to disable outputs (%pe)\n", ERR_PTR(ret));
+
+	return 0;
 }
 
 static const struct of_device_id __maybe_unused rt4831_of_match[] = {