ipvs: fix oops in backup for fwmark conn templates

	Fixes bug http://bugzilla.kernel.org/show_bug.cgi?id=10556


where conn templates with protocol=IPPROTO_IP can oops backup box.

        Result from ip_vs_proto_get() should be checked because
protocol value can be invalid or unsupported in backup. But
for valid message we should not fail for templates which use
IPPROTO_IP. Also, add checks to validate message limits and
connection state. Show state NONE for templates using IPPROTO_IP.

Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: David S. Miller <davem@davemloft.net>