Although the library documentation does not guarantee that calling
mbedtls_entropy_free() twice works, it's a plausible assumption and it's
natural to write code that frees an object twice. While this is uncommon for
an entropy context, which is usually a global variable, it came up in our
own unit tests (random_twice tests in test_suite_random).
Announce this in the same changelog entry as for RSA because it's the same
bug in the two modules.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>