Make "insert_by_date()" match "commit_list_insert()"

Same argument order, same return type.  This allows us to use a function
pointer to choose one over the other.

commit.c

@@ -147,7 +147,7 @@ void free_commit_list(struct commit_list *list)
 	}
 }
 
-void insert_by_date(struct commit_list **list, struct commit *item)
+struct commit_list * insert_by_date(struct commit *item, struct commit_list **list)
 {
 	struct commit_list **pp = list;
 	struct commit_list *p;
@@ -157,15 +157,15 @@ void insert_by_date(struct commit_list **list, struct commit *item)
 		}
 		pp = &p->next;
 	}
-	commit_list_insert(item, pp);
+	return commit_list_insert(item, pp);
 }
 
 
 void sort_by_date(struct commit_list **list)
 {
 	struct commit_list *ret = NULL;
 	while (*list) {
-		insert_by_date(&ret, (*list)->item);
+		insert_by_date((*list)->item, &ret);
 		*list = (*list)->next;
 	}
 	*list = ret;
@@ -186,7 +186,7 @@ struct commit *pop_most_recent_commit(struct commit_list **list,
 		parse_commit(commit);
 		if (!(commit->object.flags & mark)) {
 			commit->object.flags |= mark;
-			insert_by_date(list, commit);
+			insert_by_date(commit, list);
 		}
 		parents = parents->next;
 	}

commit.h

@@ -27,6 +27,7 @@ int parse_commit_buffer(struct commit *item, void *buffer, unsigned long size);
 int parse_commit(struct commit *item);
 
 struct commit_list * commit_list_insert(struct commit *item, struct commit_list **list_p);
+struct commit_list * insert_by_date(struct commit *item, struct commit_list **list);
 
 void free_commit_list(struct commit_list *list);
 
@@ -44,8 +45,6 @@ enum cmit_fmt {
 extern enum cmit_fmt get_commit_format(const char *arg);
 extern unsigned long pretty_print_commit(enum cmit_fmt fmt, const char *msg, unsigned long len, char *buf, unsigned long space);
 
-void insert_by_date(struct commit_list **list, struct commit *item);
-
 /** Removes the first commit from a list sorted by date, and adds all
  * of its parents.
  **/

epoch.c

@@ -255,11 +255,11 @@ static int find_base_for_list(struct commit_list *list, struct commit **boundary
 
 				if (!parent_node) {
 					parent_node = new_mass_counter(parent, &distribution);
-					insert_by_date(&pending, parent);
+					insert_by_date(parent, &pending);
 					commit_list_insert(parent, &cleaner);
 				} else {
 					if (!compare(&parent_node->pending, get_zero()))
-						insert_by_date(&pending, parent);
+						insert_by_date(parent, &pending);
 					add(&parent_node->pending, &parent_node->pending, &distribution);
 				}
 			}

rev-list.c

@@ -482,7 +482,7 @@ int main(int argc, char **argv)
 		commit = get_commit_reference(arg, flags);
 		if (!commit)
 			continue;
-		insert_by_date(&list, commit);
+		insert_by_date(commit, &list);
 	}
 
 	if (!merge_order) {