PVS-Studio warning V595 for DDKSamples

HRESULT
CFileContext::GetNextSubscribedMessage()
{
  ....
  m_pWdfRequest = pWdfRequest;
  m_pWdfRequest->MarkCancelable(pCallbackCancel);
  if (m_pWdfRequest != NULL)
  {
    CompleteOneArrivalEvent();
  }
  ....
}

This suspicious code was found in DDKSamples project by PVS-Studio static code analyzer.
Warning message is:
V595 The 'm_pWdfRequest' pointer was utilized before it was verified against nullptr. Check lines: 266, 267. filecontext.cpp 266

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