[PATCH 2/4] [SK_BUFF]: Introduce skb_network_header_len

For the common sequence "skb->h.raw - skb->nh.raw", similar to skb->mac_len,
that is precalculated tho, don't think we need to bloat skb with one more
member, so just use this new helper, reducing the number of non-skbuff.h
references to the layer headers even more.

Signed-off-by: Arnaldo Carvalho de Melo <redacted>
---
 drivers/net/gianfar.c                   |    2 +-
 drivers/net/pasemi_mac.c                |    4 ++--
 include/linux/skbuff.h                  |    5 +++++
 net/core/skbuff.c                       |    2 +-
 net/ipv4/ip_output.c                    |    2 +-
 net/ipv6/esp6.c                         |    3 +--
 net/ipv6/exthdrs.c                      |    8 ++++----
 net/ipv6/ip6_input.c                    |    2 +-
 net/ipv6/ip6_output.c                   |    4 ++--
 net/ipv6/mcast.c                        |    2 +-
 net/ipv6/netfilter/nf_conntrack_reasm.c |    2 +-
 net/ipv6/raw.c                          |    2 +-
 net/ipv6/reassembly.c                   |    8 +++++---
 net/ipv6/xfrm6_policy.c                 |    2 +-
 14 files changed, 27 insertions(+), 21 deletions(-)