Clean up commit insertion in git-rev-list

Jon wants the commits in a different order for merge-order.

rev-list.c

@@ -413,8 +413,10 @@ static struct commit *get_commit_reference(const char *name, unsigned int flags)
 int main(int argc, char **argv)
 {
 	struct commit_list *list = NULL;
+	struct commit_list *(*insert)(struct commit *, struct commit_list **);
 	int i, limited = 0;
 
+	insert = insert_by_date;
 	for (i = 1 ; i < argc; i++) {
 		int flags;
 		char *arg = argv[i];
@@ -464,6 +466,7 @@ int main(int argc, char **argv)
 		}
 		if (!strcmp(arg, "--merge-order")) {
 		        merge_order = 1;
+		        insert = commit_list_insert;
 			continue;
 		}
 		if (!strcmp(arg, "--show-breaks")) {
@@ -482,7 +485,7 @@ int main(int argc, char **argv)
 		commit = get_commit_reference(arg, flags);
 		if (!commit)
 			continue;
-		insert_by_date(commit, &list);
+		insert(commit, &list);
 	}
 
 	if (!merge_order) {