[IPVS]: Switch to using ctl_paths.

The feature of ipvs ctls is that the net/ipv4/vs path
is common for core ipvs ctls and for two schedulers,
so I make it exported and re-use it in modules.

Two other .c files required linux/sysctl.h to make the
extern declaration of this path compile well.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Acked-by: Simon Horman <horms@verge.net.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/ipvs/ip_vs_est.c b/net/ipv4/ipvs/ip_vs_est.c
index efdd74e..dfa0d71 100644
--- a/net/ipv4/ipvs/ip_vs_est.c
+++ b/net/ipv4/ipvs/ip_vs_est.c
@@ -18,6 +18,7 @@
 #include <linux/slab.h>
 #include <linux/types.h>
 #include <linux/interrupt.h>
+#include <linux/sysctl.h>
 
 #include <net/ip_vs.h>