power: supply: rt9455: Don't pass an error code in remove callback

When ret is not zero there were already one or two error messages emitted
about a problem (because rt9455_register_reset() emits a message in most
cases then). Passing on that error code to the i2c core only results in
another error message. Suppress that by returning zero unconditionally.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>