bridge: notifier called with the wrong device

If a new device is added to a bridge, the ethernet address of the
bridge network device may change. When the address changes, the
appropriate callback is called, but with the wrong device argument.
The address of the bridge device (ie br0) changes not the address
of the device being passed to add_if (ie eth0).

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>