[PATCH kselftest-next] selftests: cgroup: fix cleanup path in test_memcg_subtree_control()

[Roman Gushchin]

Dan reported, that cleanup path in test_memcg_subtree_control()
triggers a static checker warning:
  ./tools/testing/selftests/cgroup/test_memcontrol.c:76 \
  test_memcg_subtree_control()
  error: uninitialized symbol 'child2'.

Fix this by initializing child2 and parent2 variables and
split the cleanup path into few stages.

Signed-off-by: Roman Gushchin <g...@fb.com>
Fixes: 84092dbcf901 ("selftests: cgroup: add memory controller self-tests")
Reported-by: Dan Carpenter <dan.carpen...@oracle.com>
Cc: Dan Carpenter <dan.carpen...@oracle.com>
Cc: Shuah Khan (Samsung OSG) <sh...@kernel.org>
Cc: Mike Rapoport <r...@linux.vnet.ibm.com>
---
 .../selftests/cgroup/test_memcontrol.c        | 38 ++++++++++---------
 1 file changed, 21 insertions(+), 17 deletions(-)

diff --git a/tools/testing/selftests/cgroup/test_memcontrol.c 
b/tools/testing/selftests/cgroup/test_memcontrol.c
index 28d321ba311b..6f339882a6ca 100644
--- a/tools/testing/selftests/cgroup/test_memcontrol.c
+++ b/tools/testing/selftests/cgroup/test_memcontrol.c
@@ -26,7 +26,7 @@
  */
 static int test_memcg_subtree_control(const char *root)
 {
-       char *parent, *child, *parent2, *child2;
+       char *parent, *child, *parent2 = NULL, *child2 = NULL;
        int ret = KSFT_FAIL;
        char buf[PAGE_SIZE];
 
@@ -34,50 +34,54 @@ static int test_memcg_subtree_control(const char *root)
        parent = cg_name(root, "memcg_test_0");
        child = cg_name(root, "memcg_test_0/memcg_test_1");
        if (!parent || !child)
-               goto cleanup;
+               goto cleanup_free;
 
        if (cg_create(parent))
-               goto cleanup;
+               goto cleanup_free;
 
        if (cg_write(parent, "cgroup.subtree_control", "+memory"))
-               goto cleanup;
+               goto cleanup_parent;
 
        if (cg_create(child))
-               goto cleanup;
+               goto cleanup_parent;
 
        if (cg_read_strstr(child, "cgroup.controllers", "memory"))
-               goto cleanup;
+               goto cleanup_child;
 
        /* Create two nested cgroups without enabling memory controller */
        parent2 = cg_name(root, "memcg_test_1");
        child2 = cg_name(root, "memcg_test_1/memcg_test_1");
        if (!parent2 || !child2)
-               goto cleanup;
+               goto cleanup_free2;
 
        if (cg_create(parent2))
-               goto cleanup;
+               goto cleanup_free2;
 
        if (cg_create(child2))
-               goto cleanup;
+               goto cleanup_parent2;
 
        if (cg_read(child2, "cgroup.controllers", buf, sizeof(buf)))
-               goto cleanup;
+               goto cleanup_all;
 
        if (!cg_read_strstr(child2, "cgroup.controllers", "memory"))
-               goto cleanup;
+               goto cleanup_all;
 
        ret = KSFT_PASS;
 
-cleanup:
-       cg_destroy(child);
-       cg_destroy(parent);
-       free(parent);
-       free(child);
-
+cleanup_all:
        cg_destroy(child2);
+cleanup_parent2:
        cg_destroy(parent2);
+cleanup_free2:
        free(parent2);
        free(child2);
+cleanup_child:
+       cg_destroy(child);
+cleanup_parent:
+       cg_destroy(parent);
+cleanup_free:
+       free(parent);
+       free(child);
 
        return ret;
 }
-- 
2.17.2