discard_mntentchn(struct mntentchn *mc0) {
	struct mntentchn *mc, *mc1;

	for (mc = mc0->nxt; mc && mc != mc0; mc = mc1) {
		mc1 = mc->nxt;
		my_free_mc(mc);
	}
}
discard_mntentchn(struct mntentchn *mc0) {
	struct mntentchn *mc, *mc1;

	for (mc = mc0->nxt; mc && mc != mc0; mc = mc1) {
		mc1 = mc->nxt;
		my_free_mc(mc);
	}
}