[NETFILTER]: nf_conntrack: fix sparse warning

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/netfilter/nf_conntrack_standalone.c

@@ -384,7 +384,7 @@ static ctl_table nf_ct_netfilter_table[] = {
 	{ .ctl_name = 0 }
 };
 
-struct ctl_path nf_ct_path[] = {
+static struct ctl_path nf_ct_path[] = {
 	{ .procname = "net", .ctl_name = CTL_NET, },
 	{ }
 };