tests: submodule: fix tests for cloning submodules

The test submodule::add::homemade_clone unfortunately doesn't test
what's expected, but does instead clone the submodule to a directory
that is outside of the parent repository. Fixing this by cloning to the
correct location isn't possible, though, as `git_submodule_add_setup`
will have pre-created a ".git" file already, which will cause
`git_clone` to error out.

As it's not possible to perform the clone without fiddling around with
the repo's layout, let's just remove this test as that is in fact what
the new `git_submodule_clone` function is for.

tests/submodule/add.c

@@ -185,58 +185,6 @@ void test_submodule_add__file_exists_in_index(void)
 	git_buf_dispose(&name);
 }
 
-static int just_return_origin(git_remote **out, git_repository *repo, const char *name, const char *url, void *payload)
-{
-	GIT_UNUSED(url); GIT_UNUSED(payload);
-
-	return git_remote_lookup(out, repo, name);
-}
-
-static int just_return_repo(git_repository **out, const char *path, int bare, void *payload)
-{
-	git_submodule *sm = payload;
-
-	GIT_UNUSED(path); GIT_UNUSED(bare);
-
-	return git_submodule_open(out, sm);
-}
-
-void test_submodule_add__homemade_clone(void)
-{
-	git_clone_options clone_opts = GIT_CLONE_OPTIONS_INIT;
-	git_index *index;
-	git_oid tree_id, commit_id;
-	git_submodule *sm;
-	git_signature *sig;
-	git_repository *sm_repo;
-
-	cl_git_pass(git_repository_init(&g_repo, "willaddsubmodule", false));
-
-	/* Create the submodule structure, clone into it and finalize */
-	cl_git_pass(git_submodule_add_setup(&sm, g_repo, cl_fixture("testrepo.git"), "testrepo", true));
-
-	clone_opts.repository_cb = just_return_repo;
-	clone_opts.repository_cb_payload = sm;
-	clone_opts.remote_cb = just_return_origin;
-	clone_opts.remote_cb_payload = sm;
-	cl_git_pass(git_clone(&sm_repo, cl_fixture("testrepo.git"), "testrepo", &clone_opts));
-	cl_git_pass(git_submodule_add_finalize(sm));
-	git_repository_free(sm_repo);
-	git_submodule_free(sm);
-
-	cl_git_pass(git_repository_index(&index, g_repo));
-	cl_git_pass(git_index_write_tree(&tree_id, index));
-	git_index_free(index);
-
-	cl_git_pass(git_signature_now(&sig, "Submoduler", "submoduler@local"));
-	cl_git_pass(git_commit_create_from_ids(&commit_id, g_repo, "HEAD", sig, sig, NULL, "A submodule\n",
-										   &tree_id, 0, NULL));
-
-	git_signature_free(sig);
-
-	assert_submodule_exists(g_repo, "testrepo");
-}
-
 void test_submodule_add__submodule_clone(void)
 {
 	git_index *index;