vxlan: use a more suitable function when assigning NULL

When stopping the vxlan interface we detach it from the socket.
Use RCU_INIT_POINTER() and not rcu_assign_pointer() to do so.

Suggested-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: Mark Bloch <markb@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/vxlan.c

@@ -1077,10 +1077,10 @@ static void vxlan_sock_release(struct vxlan_dev *vxlan)
 #if IS_ENABLED(CONFIG_IPV6)
 	struct vxlan_sock *sock6 = rtnl_dereference(vxlan->vn6_sock);
 
-	rcu_assign_pointer(vxlan->vn6_sock, NULL);
+	RCU_INIT_POINTER(vxlan->vn6_sock, NULL);
 #endif
 
-	rcu_assign_pointer(vxlan->vn4_sock, NULL);
+	RCU_INIT_POINTER(vxlan->vn4_sock, NULL);
 	synchronize_net();
 
 	vxlan_vs_del_dev(vxlan);