test-cgroup: cleanup test cgroup

One test cgroup gets left behind by the test, as it moves itself
into it. Move itself and back to the original cgroup at the end
and clean up.

This fixes a failure when running the test first as root, and then
as unprivileged (initial cleanup fails as the leftover test cgroup
is owned by root).

.github/workflows/linter.yml

@@ -58,11 +58,6 @@ jobs:
           mkosi box -- mypy --version
           mkosi box -- mypy src/core/generate-bpf-delegate-configs.py src/boot/generate-hwids-section.py src/test/generate-sym-test.py src/ukify/ukify.py test/integration-tests/integration-test-wrapper.py
 
-      - name: Run ruff check
-        run: |
-          mkosi box -- ruff --version
-          mkosi box -- ruff check src/core/generate-bpf-delegate-configs.py src/boot/generate-hwids-section.py src/test/generate-sym-test.py src/ukify/ukify.py test/integration-tests/integration-test-wrapper.py
-
       - name: Run ruff format
         run: |
           mkosi box -- ruff --version
@@ -72,6 +67,11 @@ jobs:
               mkosi box -- ruff format --check --quiet --diff src/core/generate-bpf-delegate-configs.py src/boot/generate-hwids-section.py src/test/generate-sym-test.py src/ukify/ukify.py test/integration-tests/integration-test-wrapper.py
           fi
 
+      - name: Run ruff check
+        run: |
+          mkosi box -- ruff --version
+          mkosi box -- ruff check src/core/generate-bpf-delegate-configs.py src/boot/generate-hwids-section.py src/test/generate-sym-test.py src/ukify/ukify.py test/integration-tests/integration-test-wrapper.py
+
       - name: Configure meson
         run: mkosi box -- env CC=clang CXX=clang++ meson setup -Dlocalegen-path=/usr/bin/locale-gen -Dcompat-mutable-uid-boundaries=true build
 

src/test/test-cgroup.c

@@ -61,7 +61,7 @@ TEST(cg_create) {
 
         log_info("Paths for test:\n%s\n%s", test_a, test_b);
 
-        /* Possibly clean up left-overs from aboted previous runs */
+        /* Possibly clean up left-overs from aborted previous runs */
         (void) cg_trim(test_a, /* delete_root= */ true);
         (void) cg_trim(test_b, /* delete_root= */ true);
 
@@ -113,6 +113,9 @@ TEST(cg_create) {
 
         ASSERT_OK(cg_trim(test_a, true));
         ASSERT_ERROR(cg_trim(test_b, true), EBUSY);
+
+        ASSERT_OK_ZERO(cg_attach(here, 0));
+        ASSERT_OK(cg_trim(test_b, true));
 }
 
 TEST(id) {