rn_delete
rn_delete(rn->rn_key, rn->rn_mask, rnh, NULL);
rn = rn_delete(&ke->pfrke_sa, &mask, head, NULL);
rn = rn_delete(&ke->pfrke_sa, NULL, head, NULL);
rn = rn_delete(&session->ip_address, &session->ip_netmask,
struct radix_node *rn_delete(void *, void *, struct radix_node_head *,
rn_delete(&ipo->ipo_addr, &ipo->ipo_mask, rnh, rn) == NULL)