tun: annotate access to queue->trans_start

Commit 5337824 ("net: annotate accesses to queue->trans_start")
introduced a new helper, txq_trans_cond_update, to update
queue->trans_start using WRITE_ONCE. One snippet in drivers/net/tun.c
was missed, as it was introduced roughly at the same time.

Fixes: 5337824 ("net: annotate accesses to queue->trans_start")
Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: Antoine Tenart <atenart@kernel.org>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20220412135852.466386-1-atenart@kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

Author: atenart

drivers/net/tun.c

@@ -1124,7 +1124,7 @@ static netdev_tx_t tun_net_xmit(struct sk_buff *skb, struct net_device *dev)
 
 	/* NETIF_F_LLTX requires to do our own update of trans_start */
 	queue = netdev_get_tx_queue(dev, txq);
-	queue->trans_start = jiffies;
+	txq_trans_cond_update(queue);
 
 	/* Notify and wake up reader process */
 	if (tfile->flags & TUN_FASYNC)