Fixes: Timeout (19sec -> 44ms)
Fixes: 17816/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_PTX_fuzzer-5704459950227456

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