The following code is not used in current upstream code.
Some of this seems to be old hooks, other might be used by some
out of tree module (which I don't care about breaking), and
the need_ipv4_conntrack was used by old NAT code but no longer
called.
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>