This function has no more use in 'git-submodule.sh' after
bd82d7d467 (submodule: move core cmd_update() logic to C, 2021-07-20),
where we moved all of its uses to C, which has its own version for the
same.
This commit ID appears to be a reference to your own 06/13, so the OID
won't work once this is merged to git.git.
Perhaps just squash this into 06/13 instead?