PVS-Studio warning V547 for amtsdk

int ReadFileData(char* fileName, UINT8 data[], size_t size)
{
  size_t fileSize , bytesRead;
  ...
  bytesRead = read(fileno(fileHandle), data, (int) size);

  if (bytesRead < 0)
  {
    printf("Error while Reading file %s : %s",
           fileName, strerror(errno));
    bytesRead = 0;
  }
  ...
}

This suspicious code was found in amtsdk project by PVS-Studio static code analyzer.
Warning message is:
V547 Expression 'bytesRead < 0' is always false. Unsigned type value is never < 0. RemoteConsole remote.c 173

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/