bonding: Gratuitous ARP gets dropped when first slave added

When the first slave is added (such as during bootup) the first
gratuitous ARP gets dropped. We don't see this drop during a failover.
The packet gets dropped in qdisc (noop_enqueue).

The fix is to delay the sending of gratuitous ARPs till the bond dev's
carrier is present.

It can also be worked around by setting num_grat_arp to more than 1.
Signed-off-by: NVenkat Venkatsubra <venkat.x.venkatsubra@oracle.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/bonding/bond_main.c

@@ -786,6 +786,7 @@ static bool bond_should_notify_peers(struct bonding *bond)
 		   slave ? slave->dev->name : "NULL");
 
 	if (!slave || !bond->send_peer_notif ||
+	    !netif_carrier_ok(bond->dev) ||
 	    test_bit(__LINK_STATE_LINKWATCH_PENDING, &slave->dev->state))
 		return false;