Re: [PATCH 1/2] for_each_bisect_ref(): don't trim refnames

> `for_each_bisect_ref()` is called by `for_each_bad_bisect_ref()` with
> a term "bad". This used to make it call `for_each_ref_in_submodule()`
> with a prefix "refs/bisect/bad". But the latter is the name of the
> reference that is being sought, so the empty string was being passed
> to the callback as the trimmed refname. Moreover, this questionable
> practice was turned into an error by
>
>     b9c8e7f2fb prefix_ref_iterator: don't trim too much, 2017-05-22
>
> It makes more sense (and agrees better with the documentation of
> `--bisect`) for the callers to receive the full reference names. So
>
> * Add a new function, `for_each_fullref_in_submodule()`, to the refs
>   API.
>
> * Change `for_each_bad_bisect_ref()` to call the new function rather
>   than `for_each_ref_in_submodule()`.