Fixes: Timeout (128sec -> 2ms)
Fixes: 16568/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_IDCIN_fuzzer-5675004095627264

See: [FFmpeg-devel] [PATCH 4/4] tools/target_dec_fuzzer: Adjust max_pixels for IDCIN

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpegReviewed-by: Tomas Härdin <tjoppen@acc.umu.se>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>