Fixes: runtime error: left shift of 1073741838 by 1 places cannot be represented in type 'int32_t' (aka 'int')
Fixes: 3279/clusterfuzz-testcase-minimized-4564805744590848

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