[NETNS]: Consolidate kernel netlink socket destruction.

Create a specific helper for netlink kernel socket disposal. This just
let the code look better and provides a ground for proper disposal
inside a namespace.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Tested-by: Alexey Dobriyan <adobriyan@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c
index 4e5216e..e787d21 100644
--- a/net/ipv4/fib_frontend.c
+++ b/net/ipv4/fib_frontend.c
@@ -881,7 +881,7 @@
 	 * initial network namespace. So the socket will  be safe to free.
 	 */
 	net->ipv4.fibnl->sk_net = get_net(&init_net);
-	sock_release(net->ipv4.fibnl->sk_socket);
+	netlink_kernel_release(net->ipv4.fibnl);
 }
 
 static void fib_disable_ip(struct net_device *dev, int force)
diff --git a/net/ipv4/inet_diag.c b/net/ipv4/inet_diag.c
index e468e7a..605ed2c 100644
--- a/net/ipv4/inet_diag.c
+++ b/net/ipv4/inet_diag.c
@@ -935,7 +935,7 @@
 
 static void __exit inet_diag_exit(void)
 {
-	sock_release(idiagnl->sk_socket);
+	netlink_kernel_release(idiagnl);
 	kfree(inet_diag_table);
 }
 
diff --git a/net/ipv4/netfilter/ip_queue.c b/net/ipv4/netfilter/ip_queue.c
index 7361315..5109839 100644
--- a/net/ipv4/netfilter/ip_queue.c
+++ b/net/ipv4/netfilter/ip_queue.c
@@ -605,7 +605,7 @@
 	unregister_netdevice_notifier(&ipq_dev_notifier);
 	proc_net_remove(&init_net, IPQ_PROC_FS_NAME);
 cleanup_ipqnl:
-	sock_release(ipqnl->sk_socket);
+	netlink_kernel_release(ipqnl);
 	mutex_lock(&ipqnl_mutex);
 	mutex_unlock(&ipqnl_mutex);
 
@@ -624,7 +624,7 @@
 	unregister_netdevice_notifier(&ipq_dev_notifier);
 	proc_net_remove(&init_net, IPQ_PROC_FS_NAME);
 
-	sock_release(ipqnl->sk_socket);
+	netlink_kernel_release(ipqnl);
 	mutex_lock(&ipqnl_mutex);
 	mutex_unlock(&ipqnl_mutex);
 
diff --git a/net/ipv4/netfilter/ipt_ULOG.c b/net/ipv4/netfilter/ipt_ULOG.c
index fa24efa..b192756 100644
--- a/net/ipv4/netfilter/ipt_ULOG.c
+++ b/net/ipv4/netfilter/ipt_ULOG.c
@@ -415,7 +415,7 @@
 
 	ret = xt_register_target(&ulog_tg_reg);
 	if (ret < 0) {
-		sock_release(nflognl->sk_socket);
+		netlink_kernel_release(nflognl);
 		return ret;
 	}
 	if (nflog)
@@ -434,7 +434,7 @@
 	if (nflog)
 		nf_log_unregister(&ipt_ulog_logger);
 	xt_unregister_target(&ulog_tg_reg);
-	sock_release(nflognl->sk_socket);
+	netlink_kernel_release(nflognl);
 
 	/* remove pending timers and free allocated skb's */
 	for (i = 0; i < ULOG_MAXNLGROUPS; i++) {