bridge: move br_net_exit() to br.c

And it can become static.

Cc: Stephen Hemminger <stephen@networkplumber.org>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/bridge/br.c b/net/bridge/br.c
index ba780cc..19311aaf 100644
--- a/net/bridge/br.c
+++ b/net/bridge/br.c
@@ -22,14 +22,29 @@
 
 #include "br_private.h"
 
-static const struct stp_proto br_stp_proto = {
-	.rcv	= br_stp_rcv,
-};
+static void __net_exit br_net_exit(struct net *net)
+{
+	struct net_device *dev;
+	LIST_HEAD(list);
+
+	rtnl_lock();
+	for_each_netdev(net, dev)
+		if (dev->priv_flags & IFF_EBRIDGE)
+			br_dev_delete(dev, &list);
+
+	unregister_netdevice_many(&list);
+	rtnl_unlock();
+
+}
 
 static struct pernet_operations br_net_ops = {
 	.exit	= br_net_exit,
 };
 
+static const struct stp_proto br_stp_proto = {
+	.rcv	= br_stp_rcv,
+};
+
 static int __init br_init(void)
 {
 	int err;