avcodec/utils: Use 64bit for intermediate in AV_CODEC_ID_ADPCM_THP* duration calculation

Fixes: signed integer overflow: 486539264 * 14 cannot be represented in type 'int'
Fixes: 35281/clusterfuzz-testcase-minimized-ffmpeg_dem_RSD_fuzzer-6068262742917120

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

libavcodec/utils.c

@@ -712,7 +712,7 @@ static int get_audio_frame_duration(enum AVCodecID id, int sr, int ch, int ba,
             case AV_CODEC_ID_ADPCM_THP:
             case AV_CODEC_ID_ADPCM_THP_LE:
                 if (extradata)
-                    return frame_bytes * 14 / (8 * ch);
+                    return frame_bytes * 14LL / (8 * ch);
                 break;
             case AV_CODEC_ID_ADPCM_XA:
                 return (frame_bytes / 128) * 224 / ch;