Device class is ff(vend.) instead of e0(wlcon).

Output from command `usb-devices`:
T:  Bus=01 Lev=03 Prnt=03 Port=00 Cnt=01 Dev#=  6 Spd=12  MxCh= 0
D:  Ver= 2.00 Cls=ff(vend.) Sub=01 Prot=01 MxPS=64 #Cfgs=  1
P:  Vendor=05ac ProdID=8215 Rev=01.82
S:  Manufacturer=Apple Inc.
S:  Product=Bluetooth USB Host Controller
S:  SerialNumber=7C6D62936607
C:  #Ifs= 4 Cfg#= 1 Atr=e0 MxPwr=0mA
I:  If#= 0 Alt= 0 #EPs= 3 Cls=ff(vend.) Sub=01 Prot=01 Driver=btusb
I:  If#= 1 Alt= 0 #EPs= 2 Cls=e0(wlcon) Sub=01 Prot=01 Driver=btusb
I:  If#= 2 Alt= 0 #EPs= 2 Cls=ff(vend.) Sub=ff Prot=ff Driver=(none)
I:  If#= 3 Alt= 0 #EPs= 0 Cls=fe(app. ) Sub=01 Prot=00 Driver=(none)
Signed-off-by: Cyril Lacoux <clacoux@ifeelgood.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>