ci check_commit_msg: Use CI_COMMIT_SHA to avoid ambiguity

.gitlab-ci.yml

@@ -357,9 +357,10 @@ check_commit_msg:
   before_script:
     - echo "skip update submodule"
   script:
-    - git checkout ${CI_COMMIT_REF_NAME}
+    - git status
+    - git log -n10 --oneline
     # commit start with "WIP: " need to be squashed before merge
-    - 'git log --pretty=%s master..${CI_COMMIT_REF_NAME} | grep "^WIP: " || exit 0 && exit 1'
+    - 'git log --pretty=%s master.. -- | grep "^WIP: " && exit 1 || exit 0'
 
 check_submodule_sync:
   stage: deploy