The random number is intended for use by the guest. As such, we should
honor the -seed argument for reproducibility. Use the *_nofail routine
instead of rolling our own error handling locally.
Reviewed-by: Laurent Vivier <lvivier@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Reviewed-by: Cédric Le Goater <clg@kaod.org> Reviewed-by: Joel Stanley <joel@jms.id.au> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>