The 'borzoi' machine doesn't honour '-usb' in qemu so use it as an
example for the upcoming patch for removing '-usb' support.
Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Reviewed-by: Andrea Bolognani <abologna@redhat.com>