(bugtrack #2932). The interface is two USB devices in the same physical
box. Note that this is the USB ScratchAmp v1 and not the later v2
(firewire) model.
Signed-off-by: Mark Hills <mark@pogo.org.uk>
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>