[IPPCP][Library][Fix] Change iterations param in cppkcs5-pbkdf2 perf test and doc fix (#837)

Author: gbtucker

doc/source/one-way-hash-primitives.rst

@@ -231,4 +231,4 @@ the syntax.
    hash-functions
    hash-functions-for-non-streaming-messages
    mask-generation-functions
-   pkcs5-pbkdf2
+   pkcs5_pbkdf2