remote: convert get_stale_heads to take a struct refspec

Convert 'get_stale_heads()' to take a 'struct refspec' as a parameter instead
of a list of 'struct refspec_item'.

Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/builtin/remote.c b/builtin/remote.c
index 94dfcb7..b8e6658 100644
--- a/builtin/remote.c
+++ b/builtin/remote.c
@@ -347,8 +347,7 @@ static int get_ref_states(const struct ref *remote_refs, struct ref_states *stat
 		else
 			string_list_append(&states->tracked, abbrev_branch(ref->name));
 	}
-	stale_refs = get_stale_heads(states->remote->fetch.items,
-				     states->remote->fetch.nr, fetch_map);
+	stale_refs = get_stale_heads(&states->remote->fetch, fetch_map);
 	for (ref = stale_refs; ref; ref = ref->next) {
 		struct string_list_item *item =
 			string_list_append(&states->stale, abbrev_branch(ref->name));