ifq_enqueue2
int ifq_enqueue2(struct ifnet *, struct ifqueue *, struct mbuf *);
if ((error = ifq_enqueue2(&sc->sc_if, ifq, m0)) != 0) {
if ((error = ifq_enqueue2(&sc->sc_if, ifq, m)) != 0) {
if ((error = ifq_enqueue2(ifp, ifq, m)) != 0) {
error = ifq_enqueue2(ifp, ifq, m);