avcodec/ra144: Fix runtime error: signed integer overflow: -2449 * 1398101 cannot be represented in type 'int'

Fixes: 1885/clusterfuzz-testcase-minimized-5336328549957632

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
(cherry picked from commit 7c845450d2)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

libavcodec/ra144.c

@@ -1573,7 +1573,7 @@ int ff_eval_refl(int *refl, const int16_t *coefs, AVCodecContext *avctx)
             if((int)(a*(unsigned)b) != a*(int64_t)b)
                 return 1;
 #endif
-            bp1[j] = ((bp2[j] - ((refl[i+1] * bp2[i-j]) >> 12)) * b) >> 12;
+            bp1[j] = (int)((bp2[j] - ((refl[i+1] * bp2[i-j]) >> 12)) * (unsigned)b) >> 12;
         }
 
         if ((unsigned) bp1[i] + 0x1000 > 0x1fff)