turing.exe decode does not honor -- frames CL switch

[mosdav]

How to reproduce : turing.exe decode --frames 1 c:\foo.hevc
Observed behavior: decoding is keep going even after 1 frame/picture has been decoded

It seems there is no call to StateDecode::stop() (I guess it should be called once in a while during the decode loop)

bool stop() const
{
    return this->maxPictures != 0 && this->n == this->maxPictures;
}