e1000e: Correctly include VLAN_HLEN when changing interface MTU

When changing the interface mtu, the driver starts with a value
that doesn't include VLAN_HLEN.  Later tests in the driver
set the rx_buffer_len based on the mtu.  As a result, when
the user increases the mtu to 1504 (to support 802.1AD for example),
the driver rx_buffer_len does not change and frames longer
the 1522 bytes are rejected as too long.

Include VLAN_HLEN from the start so that an user mtu greater then
1500 bytes is correctly reflected in the driver rx_buffer_len.

CC: e1000-devel@lists.sourceforge.net
Signed-off-by: Vlad Yasevich <vyasevic@redhat.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/e1000e/netdev.c

@@ -5687,7 +5687,7 @@ struct rtnl_link_stats64 *e1000e_get_stats64(struct net_device *netdev,
 static int e1000_change_mtu(struct net_device *netdev, int new_mtu)
 {
 	struct e1000_adapter *adapter = netdev_priv(netdev);
-	int max_frame = new_mtu + ETH_HLEN + ETH_FCS_LEN;
+	int max_frame = new_mtu + VLAN_HLEN + ETH_HLEN + ETH_FCS_LEN;
 
 	/* Jumbo frame support */
 	if ((max_frame > ETH_FRAME_LEN + ETH_FCS_LEN) &&