openssl#5668: corrections after compiling with -qinfo=all:als.

The ongoing discussion about casting or not in PR #5626 had me compiling
again with above mentioned flags. Indeed the compiler had to say something
about it and I did these changes to silence it again.

Reviewed-by: Bernd Edlinger <bernd.edlinger@hotmail.de>
Reviewed-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/5943)