fix: fix slice init length

[jinjiadu]

What type of PR is this?

Bug fix

What does this PR do? Why is it needed?

fix slice init length

Which issues(s) does this PR fix?

Fixes #

Other notes for review

Acknowledgements

• [ ] I have read CONTRIBUTING.md.
• [ ] I have made an appropriate entry to CHANGELOG.md.
• [ ] I have added a description to this PR with sufficient context for reviewers to understand this PR.

[CLAassistant]

All committers have signed the CLA.