hv_netvsc: fix locking during VF setup

The dev_uc/mc_sync calls need to have the device address list
locked. This was spotted by running with lockdep enabled.

Fixes: bee9d41 ("hv_netvsc: propagate rx filters to VF")
Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Author: shemminger

drivers/net/hyperv/netvsc_drv.c

@@ -1851,8 +1851,12 @@ static void __netvsc_vf_setup(struct net_device *ndev,
 
 	/* set multicast etc flags on VF */
 	dev_change_flags(vf_netdev, ndev->flags | IFF_SLAVE);
+
+	/* sync address list from ndev to VF */
+	netif_addr_lock_bh(ndev);
 	dev_uc_sync(vf_netdev, ndev);
 	dev_mc_sync(vf_netdev, ndev);
+	netif_addr_unlock_bh(ndev);
 
 	if (netif_running(ndev)) {
 		ret = dev_open(vf_netdev);