e1000: Fix AMT losing connectivity when switching VLAN in passive mode

Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: NJesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: NJohn Ronciak <john.ronciak@intel.com>

drivers/net/e1000/e1000_main.c

@@ -373,7 +373,8 @@ e1000_update_mng_vlan(struct e1000_adapter *adapter)
 					(vid != old_vid) &&
 					!adapter->vlgrp->vlan_devices[old_vid])
 				e1000_vlan_rx_kill_vid(netdev, old_vid);
-		}
+		} else
+			adapter->mng_vlan_id = vid;
 	}
 }