Summary:
HashMayMatch is related to AddKey() instead of CreateFilter().
Also applies some minor Fixes#4191#4200#3910
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4202
Differential Revision: D9180945
Pulled By: maysamyabandeh
fbshipit-source-id: 6f07b81c5bb9bda5c0273475b486ba8a030471e6