PVS-Studio warning V501 for IPP Samples

int ec_fb_GetSubbandNum(void* stat)
{
  _fbECState* state = (_fbECState*)stat;
  return (state->freq - state->freq);
}

This suspicious code was found in IPP Samples project by PVS-Studio static code analyzer.
Warning message is:
V501 There are identical sub-expressions to the left and to the right of the '-' operator: state->freq - state->freq speech ec_fb.c 253

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