loopback is simple interface without logical links to other devices.
Make it using register_netdevice() to allocate unique nd_lock
for it.

loopback is converted, so 50% work of removing rtnl_lock in kernel
is done.

Signed-off-by: Kirill Tkhai <tkhai@ya.ru>
---
 drivers/net/loopback.c |    6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/net/loopback.c b/drivers/net/loopback.c
index 2b486e7c749c..c911ee7e6c68 100644
--- a/drivers/net/loopback.c
+++ b/drivers/net/loopback.c
@@ -214,7 +214,11 @@ static __net_init int loopback_net_init(struct net *net)
 		goto out;
 
 	dev_net_set(dev, net);
-	err = register_netdev(dev);
+	err = -EINTR;
+	if (rtnl_lock_killable())
+		goto out_free_netdev;
+	err = register_netdevice(dev);
+	rtnl_unlock();
 	if (err)
 		goto out_free_netdev;