static void xfrm_dst_ifdown(struct dst_entry *dst, struct net_device *dev, int unregister)
void xfrm_dst_ifdown(struct dst_entry *dst, struct net_device *dev)
static void xfrm_dst_ifdown(struct dst_entry *dst, struct net_device *dev,			    int unregister){	if (!unregister)		return;	while ((dst = dst->child) && dst->xfrm && dst->dev == dev) {		dst->dev = &loopback_dev;		dev_hold(&loopback_dev);		dev_put(dev);	}}