* cipher/blake2.c: Use const.
* cipher/camellia-glue.c, cipher/cipher.c, cipher/crc.c: Likewise.
* cipher/des.c, cipher/gost28147.c, cipher/gostr3411-94.c: Likewise.
* cipher/keccak.c, cipher/mac-cmac.c, cipher/mac-gmac.c: Likewise.
* cipher/mac-hmac.c, cipher/mac-internal.h: Likewise.
* cipher/mac-poly1305.c, cipher/mac.c, cipher/md.c: Likewise.
* cipher/md.c, cipher/md2.c, cipher/md4.c, cipher/md5.c: Likewise.
* cipher/pubkey.c, cipher/rfc2268.c, cipher/rijndael.c: Likewise.
* cipher/rmd160.c, cipher/seed.c, cipher/serpent.c: Likewise.
* cipher/sha1.c, cipher/sha256.c, cipher/sha512.c: Likewise.
* cipher/sm3.c, cipher/sm4.c, cipher/stribog.c: Likewise.
* cipher/pubkey.c, cipher/rfc2268.c, cipher/rijndael.c: Likewise.
* src/cipher-proto.h, src/cipher.h: Likewise.