libertas: name the network device wlan%d

libertas: name the network device wlan%d

Devices created by the libertas driver are currently called eth%d. Which
is wrong, because the device does not at all have anything to do with
Ethernet. And it is also confusing when used on devices with more than
one network device.

Fix this by calling it wlan%d.

Signed-off-by: Daniel Mack <daniel@caiaq.de>
Cc: Roel Kluin <roel.kluin@gmail.com>
Acked-by: Dan Williams <dcbw@redhat.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>