PVS-Studio warning V526 for Micro-Manager

const unsigned char stopSgn[2] = {0x04, 0x66};

int MotorStage::Stop()
{
  ....
  if (memcmp(stopSgn, answer, sizeof(stopSgn) != 0))
    return ERR_UNRECOGNIZED_ANSWER;
  ....
}

This suspicious code was found in Micro-Manager project by PVS-Studio static code analyzer.
Warning message is:
V526 The 'memcmp' function returns 0 if corresponding buffers are equal. Consider examining the condition for mistakes. MotorStage.cpp 385

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/