The testsuite checks for the exact size of the compressed content. The
exact size can change if the zlib library is using a different strategy.
In thise case using zlib-ng results in a slightly larger content leading
to a failure in the test.
Check that the compressed content is less than 10MiB which is a tenth of
the orignal content and proves that compression works.
Signed-off-by: Sebastian Andrzej Siewior <sebastian@breakpoint.cc>
