lf_insert
lf_insert(&lock->lf_range, range, insert_point);
lf_insert(&lock->lf_range, brange, insert_point);
lf_insert(&lock->lf_range, last_match, first_match);
lf_insert(&lock->lf_range, range, next);
static void lf_insert(struct lockf_range_list *list,