thermal_cooling_device_register() returns error encoded in a pointer
when it fails in which case we need to explictly set device->cdev
to NULL so we don't try to unregister it when unloading.
Signed-off-by: NDmitry Torokhov <dtor@mail.ru>
Acked-by: NZhang Rui <rui.zhang@intel.com>
Signed-off-by: NLen Brown <len.brown@intel.com>