submodule: inline submodule_commits() into caller

When collecting the string_list of changed submodule names, the new
submodules commits are stored in the string_list_item.util as an
oid_array. A subsequent commit will replace the oid_array with a struct
that has more information.

Prepare for this change by inlining submodule_commits() (which inserts
into the string_list and initializes the string_list_item.util) into its
only caller so that the code is easier to refactor later.

Signed-off-by: Glen Choo <chooglen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

submodule.c

@@ -782,19 +782,6 @@ const struct submodule *submodule_from_ce(const struct cache_entry *ce)
 	return submodule_from_path(the_repository, null_oid(), ce->name);
 }
 
-static struct oid_array *submodule_commits(struct string_list *submodules,
-					   const char *name)
-{
-	struct string_list_item *item;
-
-	item = string_list_insert(submodules, name);
-	if (item->util)
-		return (struct oid_array *) item->util;
-
-	/* NEEDSWORK: should we have oid_array_init()? */
-	item->util = xcalloc(1, sizeof(struct oid_array));
-	return (struct oid_array *) item->util;
-}
 
 struct collect_changed_submodules_cb_data {
 	struct repository *repo;
@@ -830,9 +817,9 @@ static void collect_changed_submodules_cb(struct diff_queue_struct *q,
 
 	for (i = 0; i < q->nr; i++) {
 		struct diff_filepair *p = q->queue[i];
-		struct oid_array *commits;
 		const struct submodule *submodule;
 		const char *name;
+		struct string_list_item *item;
 
 		if (!S_ISGITLINK(p->two->mode))
 			continue;
@@ -859,8 +846,11 @@ static void collect_changed_submodules_cb(struct diff_queue_struct *q,
 		if (!name)
 			continue;
 
-		commits = submodule_commits(changed, name);
-		oid_array_append(commits, &p->two->oid);
+		item = string_list_insert(changed, name);
+		if (!item->util)
+			/* NEEDSWORK: should we have oid_array_init()? */
+			item->util = xcalloc(1, sizeof(struct oid_array));
+		oid_array_append(item->util, &p->two->oid);
 	}
 }