Get a string describing the device which is suitable as a description of the device for the end user. The returned string should be freed with g_free() when no longer needed.
The format positional parameters are the following:
(the default format string is "%s %s %s at %d-%d")
an optional printf() format string with positional parameters
Finds the %libusb_device associated with the device.
The #SpiceUsbDevice struct is opaque and cannot be accessed directly.