This patch is to bring NETDEV_CHANGELOWERSTATE event process back
to rtnetlink_event so that bonding could use it instead of calling
rtmsg_ifinfo to send a notification to userspace after netdev lower
state is changed in the later patch.
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>