Based off how QEMU does it, look through /sys/bus/usb/devices/* for
matching vendor:product info, and if found, use info from the surrounding
files to build the device's /dev/bus/usb path.
This fixes USB device assignment by vendor:product when running qemu
as non-root (well, it should, but for some reason I couldn't reproduce
the failure people are seeing in [1], but it appears to work properly)
[1] https://bugzilla.redhat.com/show_bug.cgi?id=542450
LibVirt : simple API for virtualization
Libvirt is a C toolkit to interact with the virtualization capabilities
of recent versions of Linux (and other OSes). It is free software
available under the GNU Lesser General Public License. Virtualization of
the Linux Operating System means the ability to run multiple instances of
Operating Systems concurrently on a single hardware system where the basic
resources are driven by a Linux instance. The library aim at providing
long term stable C API initially for the Xen paravirtualization but
should be able to integrate other virtualization mechanisms if needed.
Daniel Veillard <veillard@redhat.com>