style: className optimization

[1587315093]

修改了 className 书写风格

[github-actions[bot]]

PR preview has been successfully built and deployed to https://antd-mobile-preview-pr-6396.surge.sh

[codecov[bot]]

Codecov Report

All modified lines are covered by tests :white_check_mark:

Comparison is base (88557ef) 92.36% compared to head (c8c7a80) 92.36%. Report is 2 commits behind head on master.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #6396 +/- ## ========================================== - Coverage 92.36% 92.36% -0.01% ========================================== Files 307 307 Lines 6617 6611 -6 Branches 1636 1631 -5 ========================================== - Hits 6112 6106 -6 Misses 470 470 Partials 35 35 ``` | [Files](https://app.codecov.io/gh/ant-design/ant-design-mobile/pull/6396?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=ant-design) | Coverage Δ | | |---|---|---| | [src/components/badge/badge.tsx](https://app.codecov.io/gh/ant-design/ant-design-mobile/pull/6396?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=ant-design#diff-c3JjL2NvbXBvbmVudHMvYmFkZ2UvYmFkZ2UudHN4) | `100.00% <100.00%> (ø)` | | | [src/components/button/button.tsx](https://app.codecov.io/gh/ant-design/ant-design-mobile/pull/6396?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=ant-design#diff-c3JjL2NvbXBvbmVudHMvYnV0dG9uL2J1dHRvbi50c3g=) | `93.54% <ø> (-0.21%)` | :arrow_down: | ... and [1 file with indirect coverage changes](https://app.codecov.io/gh/ant-design/ant-design-mobile/pull/6396/indirect-changes?src=pr&el=tree-more&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=ant-design)

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