fix lint

[triple-Mu]

Thanks for your contribution and we appreciate it a lot. The following instructions would make your pull request more healthy and more easily receiving feedbacks. If you do not understand some items, don't worry, just make the pull request and seek help from maintainers.

Motivation

Please describe the motivation of this PR and the goal you want to achieve through this PR.

Modification

Please briefly describe what modification is made in this PR.

BC-breaking (Optional)

Does the modification introduce changes that break the backward-compatibility of the downstream repositories?
If so, please describe how it breaks the compatibility and how the downstream projects should modify their code to keep compatibility with this PR.

Use cases (Optional)

If this PR introduces a new feature, it is better to list some use cases here, and update the documentation.

Checklist

1. Pre-commit or other linting tools are used to fix the potential lint issues.
2. The modification is covered by complete unit tests. If not, please add more unit tests to ensure the correctness.
3. If the modification has a dependency on downstream projects of a newer version, this PR should be tested with all supported versions of downstream projects.
4. The documentation has been modified accordingly, like docstring or example tutorials.

[CLAassistant]

All committers have signed the CLA.

[codecov]

Codecov Report

Base: 50.70% // Head: 50.70% // No change to project coverage 👍

Coverage data is based on head (2069f0d) compared to base (cbddf5a).
Patch has no changes to coverable lines.

Additional details and impacted files

@@           Coverage Diff            @@
##           dev-1.x    #1680   +/-   ##
========================================
  Coverage    50.70%   50.70%           
========================================
  Files          324      324           
  Lines        12255    12255           
  Branches      1817     1817           
========================================
  Hits          6214     6214           
  Misses        5607     5607           
  Partials       434      434           

Flag	Coverage Δ
unittests	50.70% <ø> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

Help us with your feedback. Take ten seconds to tell us how you rate us. Have a feature suggestion? Share it here.

☔ View full report at Codecov.
📢 Do you have feedback about the report comment? Let us know in this issue.

[irexyc]

You may also make a new pr to fix master branch

[triple-Mu]

You may also make a new pr to fix master branch

link #1685

[lvhan028]

May refer to open-mmlab/mmeval#86 to resolve isort lint issue

[lvhan028]

LGTM