qlcnic: Fix SR-IOV configuration

o Interface needs to be brought down and up while configuring SR-IOV.
Protect interface up/down using rtnl_lock()/rtnl_unlock()

Signed-off-by: Manish Chopra <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

drivers/net/ethernet/qlogic/qlcnic/qlcnic_sriov_pf.c

···
 {
 	struct net_device *netdev = adapter->netdev;
 
+	rtnl_lock();
 	if (netif_running(netdev))
 		__qlcnic_down(adapter, netdev);
 
···
 	/* After disabling SRIOV re-init the driver in default mode
 	   configure opmode based on op_mode of function
 	 */
-	if (qlcnic_83xx_configure_opmode(adapter))
+	if (qlcnic_83xx_configure_opmode(adapter)) {
+		rtnl_unlock();
 		return -EIO;
+	}
 
 	if (netif_running(netdev))
 		__qlcnic_up(adapter, netdev);
 
+	rtnl_unlock();
 	return 0;
 }
 
···
 		return -EIO;
 	}
 
+	rtnl_lock();
 	if (netif_running(netdev))
 		__qlcnic_down(adapter, netdev);
 
···
 		__qlcnic_up(adapter, netdev);
 
 error:
+	rtnl_unlock();
 	return err;
 }