Generalise the existing support for performing CBC-mode block cipher
tests, and update the code to use okx() for neater reporting of test
results.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
[test] Avoid using "static const" for test declarations
gcc will not warn about unused constant static variables. An unused
test declaration is almost certainly a bug, so ensure that warnings
are generated.
Signed-off-by: Michael Brown <mcb30@ipxe.org>