issue-8973: Added const to parameters for values that were not altered

Reviewed-by: Richard Levitte <levitte@openssl.org>
Reviewed-by: Shane Lontis <shane.lontis@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/8995)

(cherry picked from commit 5435a830765a63692b8e1e406142d1602133a5a0)