transport: mark bundle transport_options as unused

get_refs_from_bundle() is a virtual function which must match the
signature of other transports, but it doesn't look at its
transport_options at all. This isn't a bug, because not all transports
necessarily support all options. Let's mark it as unused to appease
-Wunused-parameter.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

transport.c

@@ -142,7 +142,7 @@ static void get_refs_from_bundle_inner(struct transport *transport)
 
 static struct ref *get_refs_from_bundle(struct transport *transport,
 					int for_push,
-					struct transport_ls_refs_options *transport_options)
+					struct transport_ls_refs_options *UNUSED(transport_options))
 {
 	struct bundle_transport_data *data = transport->data;
 	struct ref *result = NULL;