NG_BT_MBUFQ_DRAIN
NG_BT_MBUFQ_DRAIN(&sc->sc_cmdq);
NG_BT_MBUFQ_DRAIN(&sc->sc_aclq);
NG_BT_MBUFQ_DRAIN(&sc->sc_scoq);
NG_BT_MBUFQ_DRAIN(&unit->cmdq);
NG_BT_MBUFQ_DRAIN(&unit->cmdq);
NG_BT_MBUFQ_DRAIN((q)); \
NG_BT_MBUFQ_DRAIN(&s->outq);