netfilter: netns: shrink netns_ct struct

remove the obsolete sysctl anchors and move auto_assign_helper_warned
to avoid/cover a hole.  Reduces size by 40 bytes on 64 bit.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

include/net/netns/conntrack.h

@@ -97,18 +97,14 @@ struct netns_ct {
 	struct delayed_work ecache_dwork;
 	bool ecache_dwork_pending;
 #endif
+	bool			auto_assign_helper_warned;
 #ifdef CONFIG_SYSCTL
 	struct ctl_table_header	*sysctl_header;
-	struct ctl_table_header	*acct_sysctl_header;
-	struct ctl_table_header	*tstamp_sysctl_header;
-	struct ctl_table_header	*event_sysctl_header;
-	struct ctl_table_header	*helper_sysctl_header;
 #endif
 	unsigned int		sysctl_log_invalid; /* Log invalid packets */
 	int			sysctl_events;
 	int			sysctl_acct;
 	int			sysctl_auto_assign_helper;
-	bool			auto_assign_helper_warned;
 	int			sysctl_tstamp;
 	int			sysctl_checksum;