object: add repository argument to parse_object

Add a repository argument to allow the callers of parse_object
to be more specific about which repository to act on. This is a small
mechanical change; it doesn't change the implementation to handle
repositories other than the_repository yet.

As with the previous commits, use a macro to catch callers passing a
repository other than the_repository at compile time.

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/reflog-walk.c b/reflog-walk.c
index 5008bbf..3561a8b 100644
--- a/reflog-walk.c
+++ b/reflog-walk.c
@@ -305,7 +305,8 @@ static struct commit *next_reflog_commit(struct commit_reflog *log)
 {
 	for (; log->recno >= 0; log->recno--) {
 		struct reflog_info *entry = &log->reflogs->items[log->recno];
-		struct object *obj = parse_object(&entry->noid);
+		struct object *obj = parse_object(the_repository,
+						  &entry->noid);
 
 		if (obj && obj->type == OBJ_COMMIT)
 			return (struct commit *)obj;