Merge "Re-apply GIT_COMMIT_ID check for checkpatch" into integration

.checkpatch.conf

@@ -43,6 +43,10 @@
 # Commit messages might contain a Gerrit Change-Id.
 --ignore GERRIT_CHANGE_ID
 
+# Do not check the format of commit messages, as Gerrit's merge commits do not
+# preserve it.
+--ignore GIT_COMMIT_ID
+
 # FILE_PATH_CHANGES reports this kind of message:
 # "added, moved or deleted file(s), does MAINTAINERS need updating?"
 # We do not use this MAINTAINERS file process in TF.