staging: r8188eu: restructure mlme subfunction handling

Move some code around in rtw_mlme_ext.c to make it simpler.

mlme_sta_tbl is used only by mgt_dispatcher. Move the table inside the
function. Move mgt_dispatcher behind the handler functions. We can then
make the handler functions static.

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/20221024081417.66441-2-martin@kaiser.cx


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