PVS-Studio warning V593 for FFMpeg

static int fic_decode_frame(....)
{
  ....
  if (ret = avctx->execute(.....)) < 0)
    return ret;
  ....
}

This suspicious code was found in FFMpeg project by PVS-Studio static code analyzer.
Warning message is:
V593 Consider reviewing the expression of the 'A = B < C' kind. The expression is calculated as following: 'A = (B < C)'. fic.c 245

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