team: Fix possible deadlock during team enslave

Both dev_uc_sync_multiple() and dev_mc_sync_multiple() require the
source device to be locked by netif_addr_lock_bh(), but this is missing
in team's enslave function, so add it.

This fixes the following lockdep warning:

Possible interrupt unsafe locking scenario:

        CPU0                    CPU1
        ----                    ----
   lock(_xmit_ETHER/1);
                                local_irq_disable();
                                lock(&(&mc->mca_lock)->rlock);
                                lock(&team_netdev_addr_lock_key);
   <Interrupt>
     lock(&(&mc->mca_lock)->rlock);

  *** DEADLOCK ***

Fixes: cb41c997 ("team: team should sync the port's uc/mc addrs when add a port")
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>