avcodec/eatqi: Fix runtime error: signed integer overflow: 4466147 * 1075 cannot be represented in type 'int'

Fixes: 1443/clusterfuzz-testcase-minimized-4826998612426752

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/targets/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
(cherry picked from commit a8de60ba27)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

libavcodec/eatqi.c

@@ -112,7 +112,7 @@ static inline void tqi_idct_put(AVCodecContext *avctx, AVFrame *frame,
 
 static void tqi_calculate_qtable(TqiContext *t, int quant)
 {
-    const int qscale = (215 - 2*quant)*5;
+    const int64_t qscale = (215 - 2*quant)*5;
     int i;
 
     t->intra_matrix[0] = (ff_inv_aanscales[0] * ff_mpeg1_default_intra_matrix[0]) >> 11;