while ((cl = hif->hif_rootclass->cl_children) != NULL) {
while (hif->hif_rootclass != NULL && (cl = hif->hif_rootclass->cl_children) != NULL) {
hfsc_clear_interface(struct hfsc_if *hif){	struct hfsc_class	*cl;	/* clear out the classes */	while ((cl = hif->hif_rootclass->cl_children) != NULL) {		/*		 * remove the first leaf class found in the hierarchy		 * then start over		 */		for (; cl != NULL; cl = hfsc_nextclass(cl)) {			if (!is_a_parent_class(cl)) {				(void)hfsc_class_destroy(cl);				break;			}		}	}	return (0);}