opt: fvm: optimize FVM lanes a bit

[argse]

关联的Issues (Related Issues)

pr: 11875

改动 (Proposed Changes)

附注 (Additional Info)

自查清单 (Checklist)

在你认为本 PR 满足被审阅的标准之前，需要确保 / Before you mark the PR ready for review, please make sure that:

• [ ] 符合Venus项目管理规范中关于PR的相关标准 / The PR follows the PR standards set out in the Venus project management guidelines
• [ ] 具有清晰明确的commit message / All commits have a clear commit message.
• [ ] 包含相关的的测试用例或者不需要新增测试用例 / This PR has tests for new functionality or change in behaviour or not need to add new tests.
• [ ] 存在兼容性问题（接口, 配置，数据，灰度），如果存在需要进行文档说明 / This PR has compatibility issues (API, Configuration, Data, GrayRelease), if so, need to be documented.
• [ ] 包含相关的的指南以及文档或者不需要新增文档 / This PR has updated usage guidelines and documentation or not need
• [ ] 通过必要的检查项 / All checks are green

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 83.33333% with 1 line in your changes missing coverage. Please review.

Project coverage is 26%. Comparing base (92c5a10) to head (11a6323). Report is 4 commits behind head on feat/nv23.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## feat/nv23 #6350 +/- ## ========================================= - Coverage 26% 26% -1% ========================================= Files 649 649 Lines 65537 65532 -5 ========================================= - Hits 17085 17080 -5 + Misses 45733 45730 -3 - Partials 2719 2722 +3 ```