avcodec/wavpack: Fix runtime error: signed integer overflow: 24 * -2147483648 cannot be represented in type 'int'

Fixes: 1894/clusterfuzz-testcase-minimized-4716739789062144

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

libavcodec/wavpack.c

@@ -554,7 +554,7 @@ static inline int wv_unpack_mono(WavpackFrameContext *s, GetBitContext *gb,
             if (type != AV_SAMPLE_FMT_S16P)
                 S = T + ((s->decorr[i].weightA * (int64_t)A + 512) >> 10);
             else
-                S = T + ((s->decorr[i].weightA * A + 512) >> 10);
+                S = T + ((int)(s->decorr[i].weightA * (unsigned)A + 512) >> 10);
             if (A && T)
                 s->decorr[i].weightA -= ((((T ^ A) >> 30) & 2) - 1) * s->decorr[i].delta;
             s->decorr[i].samplesA[j] = T = S;