net: remove check for headroom in vlan_dev_create

It is possible for the headroom to be smaller then the
hard_header_len for a short period of time after toggling
the vlan offload setting.

This is not a hard error and skb_cow_head is called in
__vlan_put_tag() to resolve this.
Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Acked-by: Jesse Gross <jesse@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/8021q/vlan_dev.c

@@ -274,9 +274,6 @@ static int vlan_dev_hard_header(struct sk_buff *skb, struct net_device *dev,
 	u16 vlan_tci = 0;
 	int rc;
 
-	if (WARN_ON(skb_headroom(skb) < dev->hard_header_len))
-		return -ENOSPC;
-
 	if (!(vlan_dev_info(dev)->flags & VLAN_FLAG_REORDER_HDR)) {
 		vhdr = (struct vlan_hdr *) skb_push(skb, VLAN_HLEN);