ipvs: fix sparse warnings for some parameters

Some service fields are in network order:

- netmask: used once in network order and also as prefix len for IPv6
- port

Other parameters are in host order:

- struct ip_vs_flags: flags and mask moved between user and kernel only
- sync state: moved between user and kernel only
- syncid: sent over network as single octet

Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>