[IPV4]: Fix ipip_fb_tunnel_dev leak in ipip_fini

Signed-off-by: Patrick McHardy <kaber@trash.net>

net/ipv4/ipip.c

@@ -246,7 +246,6 @@ static struct ip_tunnel * ipip_tunnel_locate(struct ip_tunnel_parm *parms, int c
 	nt = dev->priv;
 	SET_MODULE_OWNER(dev);
 	dev->init = ipip_tunnel_init;
-	dev->destructor = free_netdev;
 	nt->parms = *parms;
 
 	if (register_netdevice(dev) < 0) {
@@ -784,6 +783,7 @@ static void ipip_tunnel_setup(struct net_device *dev)
 	dev->get_stats		= ipip_tunnel_get_stats;
 	dev->do_ioctl		= ipip_tunnel_ioctl;
 	dev->change_mtu		= ipip_tunnel_change_mtu;
+	dev->destructor		= free_netdev;
 
 	dev->type		= ARPHRD_TUNNEL;
 	dev->hard_header_len 	= LL_MAX_HEADER + sizeof(struct iphdr);