veth: Add updating of trans_start

Since commit 21a75f0 ("bonding: Fix ARP monitor validation"),
the bonding ARP / ND link monitors depend on the trans_start time to
determine link availability.  NETIF_F_LLTX drivers must update trans_start
directly, which veth does not do.  This prevents use of the ARP or ND link
monitors with veth interfaces in a bond.

	Resolve this by having veth_xmit update the trans_start time.

Reported-by: Jonathan Toppins <jtoppins@redhat.com>
Tested-by: Jonathan Toppins <jtoppins@redhat.com>
Signed-off-by: Jay Vosburgh <jay.vosburgh@canonical.com>
Fixes: 21a75f0 ("bonding: Fix ARP monitor validation")
Link: https://lore.kernel.org/netdev/b2fd4147-8f50-bebd-963a-1a3e8d1d9715@redhat.com/
Signed-off-by: David S. Miller <davem@davemloft.net>

Author: jay-vosburgh

drivers/net/veth.c

@@ -312,6 +312,7 @@ static bool veth_skb_is_eligible_for_gro(const struct net_device *dev,
 static netdev_tx_t veth_xmit(struct sk_buff *skb, struct net_device *dev)
 {
 	struct veth_priv *rcv_priv, *priv = netdev_priv(dev);
+	struct netdev_queue *queue = NULL;
 	struct veth_rq *rq = NULL;
 	struct net_device *rcv;
 	int length = skb->len;
@@ -329,6 +330,7 @@ static netdev_tx_t veth_xmit(struct sk_buff *skb, struct net_device *dev)
 	rxq = skb_get_queue_mapping(skb);
 	if (rxq < rcv->real_num_rx_queues) {
 		rq = &rcv_priv->rq[rxq];
+		queue = netdev_get_tx_queue(dev, rxq);
 
 		/* The napi pointer is available when an XDP program is
 		 * attached or when GRO is enabled
@@ -340,6 +342,8 @@ static netdev_tx_t veth_xmit(struct sk_buff *skb, struct net_device *dev)
 
 	skb_tx_timestamp(skb);
 	if (likely(veth_forward_skb(rcv, skb, rq, use_napi) == NET_RX_SUCCESS)) {
+		if (queue)
+			txq_trans_cond_update(queue);
 		if (!use_napi)
 			dev_lstats_add(dev, length);
 	} else {