message: fix unpackData max negative
diff: @@ -118,7 +118,7 @@ For normalised formats - :py:attr:`~renderdoc.CompType.UNorm` and :py:attr:`~ren
  divisor = float((2 ** (fmt.compByteWidth * 8)) - 1)
  value = tuple(float(i) / divisor for i in value)
  elif fmt.compType == rd.CompType.SNorm:
  - maxNeg = -float((2 ** (fmt.compByteWidth * 8)) - 1) / 2
  + maxNeg = -float(2 ** (fmt.compByteWidth * 8)) / 2
  divisor = float(-(maxNeg-1))
  value = tuple((float(i) if (i == maxNeg) else (float(i) / divisor)) for i in value)
  