submodule--helper: don't recreate recursive prefix
update_submodule() uses duplicated code to compute update_data->displaypath and next.recursive_prefix. The latter is just the former with "/" appended to it, and since update_data->displaypath not changed outside of this statement, we can just reuse the already computed result. We can go one step further and remove the reference to next.recursive_prefix altogether. Since it is only used in update_data_to_args() (to compute the "--recursive-prefix" flag for the recursive update child process) we can just use the already computed .displaypath value of there. Delete the duplicated code, and remove the unnecessary reference to next.recursive_prefix. As a bonus, this fixes a memory leak where prefixed_path was never freed (this leak was first reported in [1]). [1] https://lore.kernel.org/git/877a45867ae368bf9e053caedcb6cf421e02344d.1655336146.git.gitgitgadget@gmail.com Signed-off-by: Glen Choo <chooglen@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>