We are moving towards returning ERR_PTRs when i2c_new_*_device() calls
fail. Make sure its counterpart for unregistering handles ERR_PTRs as
well.
Signed-off-by: NWolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>