IPVS: ip_vs_todrop() becomes a noop when CONFIG_SYSCTL is undefined

Signed-off-by: Simon Horman <horms@verge.net.au>

include/net/ip_vs.h

@@ -1253,6 +1253,7 @@ extern int ip_vs_icmp_xmit_v6
  int offset);
 #endif
 
+#ifdef CONFIG_SYSCTL
 /*
  *	This is a simple mechanism to ignore packets when
  *	we are loaded. Just set ip_vs_drop_rate to 'n' and
@@ -1268,6 +1269,9 @@ static inline int ip_vs_todrop(struct netns_ipvs *ipvs)
 	ipvs->drop_counter = ipvs->drop_rate;
 	return 1;
 }
+#else
+static inline int ip_vs_todrop(struct netns_ipvs *ipvs) { return 0; }
+#endif
 
 /*
  *      ip_vs_fwd_tag returns the forwarding tag of the connection