PVS-Studio warning V519 for OpenH264

static inline int32_t FmoGenerateSliceGroup (....)
{
  ....
  int32_t iNumMb = 0;
  ....
  iNumMb = pFmo->iCountMbNum;
  iNumMb = kiMbWidth * kiMbHeight;
  ....
}

This suspicious code was found in OpenH264 project by PVS-Studio static code analyzer.
Warning message is:
V519 The 'iNumMb' variable is assigned values twice successively. Perhaps this is a mistake. Check lines: 127, 129. fmo.cpp 129

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/