ip6_vti: Do not use custom stat allocator

With commit 34d21de9 ("net: Move {l,t,d}stats allocation to core and
convert veth & vrf"), stats allocation could be done on net core
instead of in this driver.

With this new approach, the driver doesn't have to bother with error
handling (allocation failure checking, making sure free happens in the
right spot, etc). This is core responsibility now.

Remove the allocation in the ip6_vti and leverage the network
core allocation instead.
Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv6/ip6_vti.c

@@ -174,11 +174,6 @@ vti6_tnl_unlink(struct vti6_net *ip6n, struct ip6_tnl *t)
 	}
 }
 
-static void vti6_dev_free(struct net_device *dev)
-{
-	free_percpu(dev->tstats);
-}
-
 static int vti6_tnl_create2(struct net_device *dev)
 {
 	struct ip6_tnl *t = netdev_priv(dev);
@@ -907,9 +902,8 @@ static void vti6_dev_setup(struct net_device *dev)
 {
 	dev->netdev_ops = &vti6_netdev_ops;
 	dev->header_ops = &ip_tunnel_header_ops;
-	dev->needs_free_netdev = true;
-	dev->priv_destructor = vti6_dev_free;
 
+	dev->pcpu_stat_type = NETDEV_PCPU_STAT_TSTATS;
 	dev->type = ARPHRD_TUNNEL6;
 	dev->min_mtu = IPV4_MIN_MTU;
 	dev->max_mtu = IP_MAX_MTU - sizeof(struct ipv6hdr);
@@ -931,9 +925,6 @@ static inline int vti6_dev_init_gen(struct net_device *dev)
 
 	t->dev = dev;
 	t->net = dev_net(dev);
-	dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
-	if (!dev->tstats)
-		return -ENOMEM;
 	netdev_hold(dev, &t->dev_tracker, GFP_KERNEL);
 	netdev_lockdep_set_classes(dev);
 	return 0;