This fixes a crash when recording fifologs, as the mutex is acquired when BPWritten calls AfterFrameEvent::Trigger, but then acquired again when FifoRecorder::EndFrame calls m_end_of_frame_event.reset(). std::mutex does not allow calling lock() if the thread already owns the mutex, while std::recursive_mutex does allow this.
This is a regression from #11522 (which introduced the HookableEvent system).
