SHA-3 is not a symmetric cipher.

SHA-3 is not a symmetric cipher.
Fix a copy and paste mistake that Ronald Tse introduced in 2017 even
though Richard Levitte and Bernd Edlinger reviewed his commit - and that
i unwittingly copied.  Even in the OpenSSL 3 main trunk, it wasn't fixed
until 2022, and in OpenSSL-1.1.1, it is still wrong.
Unfortunately, we need to be really careful before believing anything
the OpenSSL documentation says...