Update secmemtest and memeleaktest to use the test infrastructure.

Update secmemtest and memeleaktest to use the test infrastructure.

It isn't easy to use the test framework since it turns memory debugging
on as well and the CRYPTO_mem_leaks_fp function cannot be called twice.

Reviewed-by: Richard Levitte <levitte@openssl.org>
Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/3169)