IPVS: Backup, adding version 0 sending capabilities

This patch adds a sysclt net.ipv4.vs.sync_version
that can be used to send sync msg in version 0 or 1 format.

sync_version value is logical,
     Value 1 (default) New version
           0 Plain old version

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>
diff --git a/include/net/ip_vs.h b/include/net/ip_vs.h
index a715f3d..d858264 100644
--- a/include/net/ip_vs.h
+++ b/include/net/ip_vs.h
@@ -883,7 +883,9 @@
 extern int sysctl_ip_vs_snat_reroute;
 extern struct ip_vs_stats ip_vs_stats;
 extern const struct ctl_path net_vs_ctl_path[];
+extern int sysctl_ip_vs_sync_ver;
 
+extern void ip_vs_sync_switch_mode(int mode);
 extern struct ip_vs_service *
 ip_vs_service_get(int af, __u32 fwmark, __u16 protocol,
 		  const union nf_inet_addr *vaddr, __be16 vport);