vxlan: Do not alloc tstats manually

With commit 34d21de99c ("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 vxlan driver and leverage the network
core allocation instead.

Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Subbaraya Sundeep <sbhatta@marvell.com>
Link: https://lore.kernel.org/r/20240311112437.3813987-1-leitao@debian.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/vxlan/vxlan_core.c

@@ -2841,15 +2841,9 @@ static int vxlan_init(struct net_device *dev)
 	if (vxlan->cfg.flags & VXLAN_F_VNIFILTER)
 		vxlan_vnigroup_init(vxlan);
 
-	dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
-	if (!dev->tstats) {
-		err = -ENOMEM;
-		goto err_vnigroup_uninit;
-	}
-
 	err = gro_cells_init(&vxlan->gro_cells, dev);
 	if (err)
-		goto err_free_percpu;
+		goto err_vnigroup_uninit;
 
 	err = vxlan_mdb_init(vxlan);
 	if (err)
@@ -2860,8 +2854,6 @@ static int vxlan_init(struct net_device *dev)
 
 err_gro_cells_destroy:
 	gro_cells_destroy(&vxlan->gro_cells);
-err_free_percpu:
-	free_percpu(dev->tstats);
 err_vnigroup_uninit:
 	if (vxlan->cfg.flags & VXLAN_F_VNIFILTER)
 		vxlan_vnigroup_uninit(vxlan);
@@ -2892,8 +2884,6 @@ static void vxlan_uninit(struct net_device *dev)
 	gro_cells_destroy(&vxlan->gro_cells);
 
 	vxlan_fdb_delete_default(vxlan, vxlan->cfg.vni);
-
-	free_percpu(dev->tstats);
 }
 
 /* Start ageing timer and join group when device is brought up */
@@ -3316,6 +3306,7 @@ static void vxlan_setup(struct net_device *dev)
 	dev->min_mtu = ETH_MIN_MTU;
 	dev->max_mtu = ETH_MAX_MTU;
 
+	dev->pcpu_stat_type = NETDEV_PCPU_STAT_TSTATS;
 	INIT_LIST_HEAD(&vxlan->next);
 
 	timer_setup(&vxlan->age_timer, vxlan_cleanup, TIMER_DEFERRABLE);