staging: r8188eu: simplify rtw_get_ff_hwaddr

staging: r8188eu: simplify rtw_get_ff_hwaddr

On both occassions where rtw_get_ff_hwaddr is called, the result is used
as addr parameter for rtw_write_port. rtw_write_port only needs the info
if the high queue was used or not. Simplify rtw_get_ff_hwaddr accordingly
and remove the now unused queue defines.

Signed-off-by: Martin Kaiser <martin@kaiser.cx>
Tested-by: Philipp Hortmann <philipp.g.hortmann@gmail.com> # Edimax N150
Link: https://lore.kernel.org/r/20230207192319.294203-7-martin@kaiser.cx
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>