staging: r8188eu: remove unused define

Remove the rtw_dequeue_recvframe define, which is not used.

Signed-off-by: Martin Kaiser <martin@kaiser.cx>
Link: https://lore.kernel.org/r/20220226181457.1138035-8-martin@kaiser.cx


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