staging:r8188eu: replace enum WIFI_STATUS_CODE with native kernel definitions

Driver and kernel definitions are equal.
Avoid code duplication, improve readability.

Signed-off-by: Ivan Safonov <insafonov@gmail.com>
Link: https://lore.kernel.org/r/20210131080618.25184-1-insafonov@gmail.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>