netfilter: nf_conntrack: remove unused ctl_table_path member in nf_conntrack_l3proto

After commit adf05168 ("netfilter: remove ip_conntrack* sysctl
compat code"), ctl_table_path member in struct nf_conntrack_l3proto{}
is not used anymore, remove it.
Signed-off-by: NLiping Zhang <liping.zhang@spreadtrum.com>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

include/net/netfilter/nf_conntrack_l3proto.h

@@ -63,10 +63,6 @@ struct nf_conntrack_l3proto {
 
 	size_t nla_size;
 
-#ifdef CONFIG_SYSCTL
-	const char		*ctl_table_path;
-#endif /* CONFIG_SYSCTL */
-
 	/* Init l3proto pernet data */
 	int (*init_net)(struct net *net);