IPVS: netns, connection hash got net as param.

Connection hash table is now name space aware.
i.e. net ptr >> 8 is xor:ed to the hash,
and this is the first param to be compared.
The net struct is 0xa40 in size ( a little bit smaller for 32 bit arch:s)
and cache-line aligned, so a ptr >> 5 might be a more clever solution ?

All lookups where net is compared uses net_eq() which returns 1 when netns
is disabled, and the compiler seems to do something clever in that case.

ip_vs_conn_fill_param() have *net as first param now.

Three new inlines added to keep conn struct smaller
when names space is disabled.
- ip_vs_conn_net()
- ip_vs_conn_net_set()
- ip_vs_conn_net_eq()

*v3
  moved net compare to the end in "fast path"

Signed-off-by: Hans Schillstrom <hans.schillstrom@ericsson.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>