PVS-Studio warning V529 for QuickThread

QuickThreadCallNodeQueue* getCallNodeQueue(Affinities_bm& bm)
{
  ....
  if(temp->owningThreadNumber < 0);
    temp->owningThreadNumber = 0;
  ....
}

This suspicious code was found in QuickThread project by PVS-Studio static code analyzer.
Warning message is:
V529 Odd semicolon ';' after 'if' operator. quickthread.cpp 670

PVS-Studio is a static analyzer for detecting bugs in the source code of applications written in C, C++, C++11, C++/CX. Site: http://www.viva64.com/en/pvs-studio/