avcodec/asvdec: Use rounded up dimenensions in input size check

Fixes: Timeout
Fixes: 2001/clusterfuzz-testcase-minimized-6187599389523968

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

libavcodec/asvdec.c

@@ -210,7 +210,7 @@ static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
     AVFrame *const p = data;
     int mb_x, mb_y, ret;
 
-    if (buf_size * 8LL < a->mb_height2 * a->mb_width2 * 13LL)
+    if (buf_size * 8LL < a->mb_height * a->mb_width * 13LL)
         return AVERROR_INVALIDDATA;
 
     if ((ret = ff_get_buffer(avctx, p, 0)) < 0)