avcodec/twinvqdec: Correct overflow in block align check

Fixes: signed integer overflow: 538976288 * 8 cannot be represented in type 'int'
Fixes: 19126/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_TWINVQ_fuzzer-5687464110325760

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

libavcodec/twinvqdec.c

@@ -404,7 +404,7 @@ static av_cold int twinvq_decode_init(AVCodecContext *avctx)
     tctx->frame_size     = avctx->bit_rate * tctx->mtab->size
                                            / avctx->sample_rate + 8;
     tctx->is_6kbps       = 0;
-    if (avctx->block_align && avctx->block_align * 8 / tctx->frame_size > 1) {
+    if (avctx->block_align && avctx->block_align * 8LL / tctx->frame_size > 1) {
         av_log(avctx, AV_LOG_ERROR,
                "VQF TwinVQ should have only one frame per packet\n");
         return AVERROR_INVALIDDATA;