staging: r8188eu: remove unused DEBUG_OID macro

The DEBUG_OID macro is not used and can be removed.

Signed-off-by: Martin Kaiser <martin@kaiser.cx>
Link: https://lore.kernel.org/r/20210807153636.11712-12-martin@kaiser.cx


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