Summary:
CreateFileChecksumGenerator may uses requested_checksum_func_name in generator context to decide which generator will be used. GenerateOneFileChecksum has not being updated to use it, which will always get the generator when the name is empty. Fix it.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7586
Test Plan: make check
Reviewed By: riversand963
Differential Revision: D24491989
Pulled By: zhichao-cao
fbshipit-source-id: d9fdfdd431240f0a9a2e781ddbd48a7d6c609aad