clist_nextc
cp = clist_nextc(&tp->t_rawq, NULL, &tabc);
cp = clist_nextc(&tp->t_rawq,
cp = clist_nextc(&tp->t_canq, NULL, &c);
cp = clist_nextc(&tp->t_canq, cp, &c);
cp = clist_nextc(&tp->t_rawq, NULL, &c);
cp = clist_nextc(&tp->t_rawq, cp, &c);
void *clist_nextc (struct clist *q, void *cp, int *c);