[PATCH] use core driver name for ATM device

[Duncan Sands]

Hi Roman, good catch.

> This one-liner fixes the case when subdriver's module gets unloaded,
> thus its .driver_name gets destroyed, while ATM still holds a reference
> to it.  It passes instead usbatm_driver_name to ATM.
> 
> Alternatively we can make a private copy of subdriver's .driver_name and
> release it in usbatm_destroy_instance, but it doesn't seem to be worth
> to bother.

let me check where this information is seen...  maybe it is useful to know
which minidriver is being used.

Ciao,

Duncan.