THis patch (as1270) allows the usbtest module to be built even when
USB_DEVICEFS isn't configured.  Tests can be performed without
USB_DEVICEFS, using the /dev/bus/usb/*/* device files.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>