Merge branch 'bpf-push-pop-helpers'

Merge branch 'bpf-push-pop-helpers'

Alexei Starovoitov says:

====================
bpf: introduce bpf_skb_vlan_push/pop() helpers

Let TC+eBPF programs call skb_vlan_push/pop via helpers.

v1->v2:
- reworded commit log to better explain correctness of re-caching
  and fixed comparison of mixed endiannes (suggested by Eric)
====================

Signed-off-by: David S. Miller <davem@davemloft.net>