drivers: vxlan: fix returnvar.cocci warning

Fix the following coccicheck warning:

drivers/net/vxlan/vxlan_core.c:2995:5-8:
Unneeded variable: "ret". Return "0" on line 3004.

Fixes: f9c4bb0b ("vxlan: vni filtering support on collect metadata device")
Signed-off-by: Guo Zhengkui <guozhengkui@vivo.com>
Acked-by: Roopa Prabhu <roopa@nvidia.com>
Link: https://lore.kernel.org/r/20220308134321.29862-1-guozhengkui@vivo.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/vxlan/vxlan_core.c

@@ -2990,7 +2990,6 @@ static void vxlan_flush(struct vxlan_dev *vxlan, bool do_all)
 static int vxlan_stop(struct net_device *dev)
 {
 	struct vxlan_dev *vxlan = netdev_priv(dev);
-	int ret = 0;
 
 	vxlan_multicast_leave(vxlan);
 
@@ -2999,7 +2998,7 @@ static int vxlan_stop(struct net_device *dev)
 	vxlan_flush(vxlan, false);
 	vxlan_sock_release(vxlan);
 
-	return ret;
+	return 0;
 }
 
 /* Stub, nothing needs to be done. */