testsuite: add test for zstd-compressed module
testsuite: add test for zstd-compressed module

I took away one module from the gzip-compressed modules for this purpose.

Signed-off-by: Torge Matthies <4247b505170df294ca62c9d00925c0aa11ef884b@googlemail.com>

lucasdemarchi/kmod,lucasdemarchi/kmod,lucasdemarchi/kmod