platform/chrome: cros_ec: Make cros_ec_unregister() return void

[ Upstream commit afb0a80e ]

Up to now cros_ec_unregister() returns zero unconditionally. Make it
return void instead which makes it easier to see in the callers that
there is no error to handle.

Also the return value of i2c, platform and spi remove callbacks is
ignored anyway.

Reviewed-by: Guenter Roeck <groeck@chromium.org>
Link: https://lore.kernel.org/r/20211020071753.wltjslmimb6wtlp5@pengutronix.de


Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20220123175201.34839-5-u.kleine-koenig@pengutronix.de


Signed-off-by: Mark Brown <broonie@kernel.org>
Stable-dep-of: e2374953 ("platform/chrome: cros_ec: Unregister notifier in cros_ec_unregister()")
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>