The implementation of nand_release() already call mtd_device_unregister(),
no need to call it again.
Signed-off-by: NAxel Lin <axel.lin@gmail.com>
Acked-by: NJamie Iles <jamie@jamieiles.com>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>