avcodec/mvha: Check remaining bits in VLC decode loop

Fixes: timeout (252sec -> 170msec)
Fixes: 20023/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_MVHA_fuzzer-5681192565473280

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

libavcodec/mvha.c

@@ -233,6 +233,8 @@ static int decode_frame(AVCodecContext *avctx,
 
             dst = frame->data[p] + (avctx->height - 1) * frame->linesize[p];
             for (int y = 0; y < avctx->height; y++) {
+                if (get_bits_left(gb) < width)
+                    return AVERROR_INVALIDDATA;
                 for (int x = 0; x < width; x++) {
                     int v = get_vlc2(gb, s->vlc.table, s->vlc.bits, 3);