tag: add repository argument to deref_tag

Add a repository argument to allow the callers of deref_tag
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/server-info.c b/server-info.c
index 2abd0dc..41050c2 100644
--- a/server-info.c
+++ b/server-info.c
@@ -64,7 +64,7 @@ static int add_info_ref(const char *path, const struct object_id *oid,
 		return -1;
 
 	if (o->type == OBJ_TAG) {
-		o = deref_tag(o, path, 0);
+		o = deref_tag(the_repository, o, path, 0);
 		if (o)
 			if (fprintf(fp, "%s	%s^{}\n",
 				oid_to_hex(&o->oid), path) < 0)