We'll just exit with an error anyway, so it doesn't really matter, but it
is cleaned up in all of the other places were we error out.

Signed-off-by: Luke Shumaker <lukeshu@parabola.nu>
Message-Id: <20171228180814.9749-4-lukeshu@lukeshu.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>