Validate the size macros directly from the output length in the test data,
rather than using the value returned by the library. This is equivalent
since the value returned by the library is checked to be identical.
Enforce that SIZE() <= MAX_SIZE(), in addition to length <= SIZE(). This is
stronger than the previous code which merely enforced length <= SIZE() and
length <= MAX_SIZE().
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>