allocnode
pn_new = allocnode(pu, pn, pcn->pcn_name, va);
pn_new = allocnode(pu, pn, pcn->pcn_name, va);
pn = allocnode(pu, pn_dir, pcn->pcn_name, &va);
pn_new = allocnode(pu, pn, pcn->pcn_name, va);
struct puffs_node *allocnode(struct puffs_usermount *, struct puffs_node *,