This patch changes the name of the proc file for each ibmveth adapter
from the network device name to the slot number in the virtual bus.

The proc file is created when the device is probed, so a change
in the name of the device will not be reflected in the name of the
proc file giving problems when identifying and removing the adapter.
The slot number is a property that does not change through the life
of the adapter so we use that instead.
Signed-off-by: Santiago Leon <santil@us.ibm.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>