fix: DecodeRLP can panic

[simlecode]

关联的Issues (Related Issues)

lotus pr: 11079

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

Merging #6125 (0e1e1af) into feat/nv21 (3ad5dc8) will increase coverage by 0%.
The diff coverage is 100%.

Additional details and impacted files

@@            Coverage Diff            @@
##           feat/nv21   #6125   +/-   ##
=========================================
  Coverage         24%     24%           
=========================================
  Files            663     663           
  Lines          80943   80932   -11     
=========================================
- Hits           19783   19781    -2     
+ Misses         58532   58521   -11     
- Partials        2628    2630    +2