The driver core ignores the return value of struct device_driver::remove
because there is only little that can be done. To simplify the quest to
make this function return void, let struct sa1111_driver::remove return
void, too. All users already unconditionally return 0, this commit makes
it obvious that returning an error code is a bad idea and ensures future
users behave accordingly.

Link: https://lore.kernel.org/r/20201126114724.2028511-1-u.kleine-koenig@pengutronix.deAcked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>