Fixes: memleaks
Fixes: 18332/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_ATRAC3P_fuzzer-5655654374572032

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