netfilter: make /proc/net/netfilter pernet

This patch makes this proc dentry pernet. So far only init_net
had a /proc/net/netfilter directory.

Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

include/net/netns/netfilter.h

@@ -0,0 +1,11 @@
+#ifndef __NETNS_NETFILTER_H
+#define __NETNS_NETFILTER_H
+
+#include <linux/proc_fs.h>
+
+struct netns_nf {
+#if defined CONFIG_PROC_FS
+	struct proc_dir_entry *proc_netfilter;
+#endif
+};
+#endif