[FFmpeg-cvslog] dnn_backend_native: Add overflow check for length calculation.

ffmpeg | branch: release/4.3 | Reimar Döffinger | Mon Jul 6 09:32:17 2020 +0200| [1f32d8ea2328843f5741029278fd146aba19e8d0] | committer: Guo, Yejun dnn_backend_native: Add overflow check for length calculation. We should not silently allocate an incorrect sized buffer. Fixes trac issue #8718.

[FFmpeg-cvslog] dnn_backend_native: Add overflow check for length calculation.

ffmpeg | branch: master | Reimar Döffinger | Mon Jul 6 09:32:17 2020 +0200| [584f396132aa19d21bb1e38ad9a5d428869290cb] | committer: Guo, Yejun dnn_backend_native: Add overflow check for length calculation. We should not silently allocate an incorrect sized buffer. Fixes trac issue #8718. Sig