The @result parameter passed to hash/hmac APIs may either contain
a pre-allocated buffer, or a buffer can be allocated on the fly.
Clarify these two different usage models in the API docs.
Reviewed-by: Dorjoy Chowdhury <dorjoychy111@gmail.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
769660955a