message: videoio(MSMF): remove "always true" check
diff: @@ -1056,18 +1056,15 @@ HRESULT SourceReaderCB::Wait(DWORD dwMilliseconds, _ComPtr<IMFSample>& videoSamp
  return HRESULT_FROM_WIN32(GetLastError());
  }
  - if (!bEOS)
  - {
  - cv::AutoLock lock(m_mutex);
  bEOS = m_bEOS;
  if (!bEOS)
  {
  + cv::AutoLock lock(m_mutex);
  videoSample = m_lastSample;
  CV_Assert(videoSample);
  m_lastSample.Release();
  ResetEvent(m_hEvent); // event is auto-reset, but we need this forced reset due time gap between wait() and mutex hold.
  }
  - }
  return m_hrStatus;
  }
  