[github] fix lint rule (#7)

.github/workflows/lint.yml

@@ -54,16 +54,8 @@ jobs:
           set -eux
           pip install flake8==3.8.2 flake8-bugbear flake8-comprehensions flake8-executable flake8-pyi==20.5.0 mccabe pycodestyle==2.6.0 pyflakes==2.2.0
           flake8 --version
-          flake8 | tee ${GITHUB_WORKSPACE}/flake8-output.txt
-      - name: Add annotations
-        uses: pytorch/add-annotations-github-action@master
-        with:
-          check_name: 'flake8-py3'
-          linter_output_path: 'flake8-output.txt'
-          commit_sha: ${{ steps.get_pr_tip.outputs.commit_sha }}
-          regex: '^(?<filename>.*?):(?<lineNumber>\d+):(?<columnNumber>\d+): (?<errorCode>\w\d+) (?<errorDesc>.*)'
-        env:
-          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          flake8
+          if [ $? != 0 ]; then exit 1; fi
 
   cpplint:
     runs-on: ubuntu-latest