ffmpeg libyami can't run stream loop.

[zhtang83]

run command:
./ffmpeg -y -stream_loop 5 -c:v libyami_h264 -i skyfall2-trailer.mp4 -an -f null /dev/null

the stream has 3614 frames, run above command, ffmpeg decode 3614 frames and exit, it should be decode 3614 x 5 frames.