The old test code raises two compiler warnings which are errors since
commit 417c9d72.

These errors could result in compilations with compiler flag
-march486 (so all nice features of newer processors got lost).
Signed-off-by: NStefan Weil <sw@weilnetz.de>
Reviewed-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NBlue Swirl <blauwirbel@gmail.com>