if_delmulti_locked
if_delmulti_locked(ifp, ifma, 1);
static int if_delmulti_locked(struct ifnet *, struct ifmultiaddr *, int);
lastref = if_delmulti_locked(ifp, ifma, 0);
if_delmulti_locked(ifp, ifma, 0);
lastref = if_delmulti_locked(ifp, ifma, flags);