run-command API: move *_tr2() users to "run_processes_parallel()"

Have the users of the "run_processes_parallel_tr2()" function use
"run_processes_parallel()" instead. In preceding commits the latter
was refactored to take a "struct run_process_parallel_opts" argument,
since the only reason for "run_processes_parallel_tr2()" to exist was
to take arguments that are now a part of that struct we can do away
with it.

See ee4512ed48 (trace2: create new combined trace facility,
2019-02-22) for the addition of the "*_tr2()" variant of the function,
it was used by every caller except "t/helper/test-run-command.c"..

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

submodule.c

@@ -1819,6 +1819,17 @@ int fetch_submodules(struct repository *r,
 {
 	int i;
 	struct submodule_parallel_fetch spf = SPF_INIT;
+	const struct run_process_parallel_opts opts = {
+		.tr2_category = "submodule",
+		.tr2_label = "parallel/fetch",
+
+		.processes = max_parallel_jobs,
+
+		.get_next_task = get_next_submodule,
+		.start_failure = fetch_start_failure,
+		.task_finished = fetch_finish,
+		.data = &spf,
+	};
 
 	spf.r = r;
 	spf.command_line_option = command_line_option;
@@ -1840,12 +1851,7 @@ int fetch_submodules(struct repository *r,
 
 	calculate_changed_submodule_paths(r, &spf.changed_submodule_names);
 	string_list_sort(&spf.changed_submodule_names);
-	run_processes_parallel_tr2(max_parallel_jobs,
-				   get_next_submodule,
-				   fetch_start_failure,
-				   fetch_finish,
-				   &spf,
-				   "submodule", "parallel/fetch");
+	run_processes_parallel(&opts);
 
 	if (spf.submodules_with_errors.len > 0)
 		fprintf(stderr, _("Errors during submodule fetch:\n%s"),