avformat/rmdec: use larger intermediate type for audio_framesize * sub_packet_h check
Fixes: signed integer overflow: 65535 * 65535 cannot be represented in type 'int'
Fixes: 31406/clusterfuzz-testcase-minimized-ffmpeg_dem_IVR_fuzzer-
5024692843970560
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
cf2fd9204b3c707d9e414583b043ee88b8e8c52e)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>