RocksDB Version: 6.29.3
OS: Linux Kernel 3.10.0-1127.el7.x86_64

In ErrorHandler::RecoverFromRetryableBGIOError，if end_recovery_ flag is true, recovery_thread_ will exist and recovery_in_prog _ flag remain false.

So, in DBImpl::CloseHelper，after error_handler_.CancelErrorRecovery() and join recovery_thread_，code path will hang on bg_cv_Wait().