Work around Windows build issues
At least MinGW did not have ENOTCONN, EOPNOTSUPP, ECANCELED, so define
these to allow the build to go through.
wpas_rrm_send_neighbor_rep_request() is not really used on Windows, so
the exact error code values do not make any difference here.
Signed-off-by: Jouni Malinen <j@w1.fi>