net/bonding: emit address change event also in bond_release

commit 7d26bb10 "bonding: emit event when bonding changes MAC" didn't
take care to emit the NETDEV_CHANGEADDR event in bond_release, where bonding
actually changes the mac address (to all zeroes). As a result the neighbours
aren't deleted by the core networking code (which does so upon getting that
event).
Signed-off-by: NShlomo Pongratz <shlomop@mellanox.com>
Signed-off-by: NJay Vosburgh <fubar@us.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/bonding/bond_main.c

@@ -2034,6 +2034,9 @@ int bond_release(struct net_device *bond_dev, struct net_device *slave_dev)
 	write_unlock_bh(&bond->lock);
 	unblock_netpoll_tx();
 
+	if (bond->slave_cnt == 0)
+		call_netdevice_notifiers(NETDEV_CHANGEADDR, bond->dev);
+
 	bond_compute_features(bond);
 	if (!(bond_dev->features & NETIF_F_VLAN_CHALLENGED) &&
 	    (old_features & NETIF_F_VLAN_CHALLENGED))