lint: don't fail workflow on indent fail

There are multiple cases where good human readable code block is
converted to an unreadable mess by clang-format, so we don't want to
rely on clang-format completely. Also there is no way, as far as I can
see, to make clang-format only fix what we want it to fix without
breaking something.

So let's just display hints inline where clang-format is unhappy. When
reviewer sees such a warning it's a good sign that something is broken
in coding-style around this warning.

We add special script which parses diff generated by indent and
generates warning for each hunk.

Signed-off-by: Pavel Tikhomirov <ptikhomirov@virtuozzo.com>

.github/workflows/lint.yml

@@ -26,15 +26,15 @@ jobs:
       run: make lint
 
     - name: Run make indent
-      run: >
+      continue-on-error: true
+      run: |
         if [ -z "${{github.base_ref}}" ]; then
-          git fetch --deepen=1 &&
-          if ! make indent OPTS=--diff; then
-            exit 1
-          fi
+          git fetch --deepen=1
+          make indent
         else
-          git fetch origin ${{github.base_ref}} &&
-          if ! make indent OPTS=--diff BASE=origin/${{github.base_ref}}; then
-            exit 1
-          fi
+          git fetch origin ${{github.base_ref}}
+          make indent BASE=origin/${{github.base_ref}}
         fi
+    - name: Raise in-line make indent warnings
+      run: |
+        git diff | ./scripts/github-indent-warnings.py