vlan: cleanup the usage of vlan_dev_priv(dev)

This patch cleanup 2 points for the usage of vlan_dev_priv(dev):
* In vlan_dev.c/vlan_dev_hard_header, we should use the var *vlan directly
  after grabing the pointer at the beginning with
        *vlan = vlan_dev_priv(dev);
  when we need to access the fields of *vlan.
* In vlan.c/register_vlan_device, add the var *vlan pointer
        struct vlan_dev_priv *vlan;
to cleanup the code to access the fields of vlan_dev_priv(new_dev).

Signed-off-by: Wang Sheng-Hui <shhuiw@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/8021q/vlan_dev.c

@@ -107,10 +107,10 @@ static int vlan_dev_hard_header(struct sk_buff *skb, struct net_device *dev,
 	u16 vlan_tci = 0;
 	int rc;
 
-	if (!(vlan_dev_priv(dev)->flags & VLAN_FLAG_REORDER_HDR)) {
+	if (!(vlan->flags & VLAN_FLAG_REORDER_HDR)) {
 		vhdr = (struct vlan_hdr *) skb_push(skb, VLAN_HLEN);
 
-		vlan_tci = vlan_dev_priv(dev)->vlan_id;
+		vlan_tci = vlan->vlan_id;
 		vlan_tci |= vlan_dev_get_egress_qos_mask(dev, skb);
 		vhdr->h_vlan_TCI = htons(vlan_tci);
 
@@ -133,7 +133,7 @@ static int vlan_dev_hard_header(struct sk_buff *skb, struct net_device *dev,
 		saddr = dev->dev_addr;
 
 	/* Now make the underlying real hard header */
-	dev = vlan_dev_priv(dev)->real_dev;
+	dev = vlan->real_dev;
 	rc = dev_hard_header(skb, dev, type, daddr, saddr, len + vhdrlen);
 	if (rc > 0)
 		rc += vhdrlen;