OpenSSL: Fix memory leak in HMAC_CTX compatibility wrapper function

OpenSSL: Fix memory leak in HMAC_CTX compatibility wrapper function

Commit 5c9a33702fd9e9ae9c349d6461a6621801d4f9cb ('OpenSSL: Clean up
crypto_hash_*() to use a single implementation') added a wrapper
function to allow the new OpenSSL API to be used with older OpenSSL
versions. However, the HMAC_CTX_free() wrapper was incorrectly skipping
the call to HMAC_CTX_cleanup() which is still needed to free the
resources OpenSSL allocated internally.

Signed-off-by: Jouni Malinen <jouni@qca.qualcomm.com>