Fix bench.

Author: tnull

lightning/src/ln/channelmanager.rs

@@ -7454,7 +7454,7 @@ pub mod bench {
 				let seed = [3u8; 32];
 				let keys_manager = KeysManager::new(&seed, 42, 42);
 				let random_seed_bytes = keys_manager.get_secure_random_bytes();
-				let route = get_route(&$node_a.get_our_node_id(), &payment_params, &dummy_graph,
+				let route = get_route(&$node_a.get_our_node_id(), &payment_params, &dummy_graph.read_only(),
 					Some(&usable_channels.iter().map(|r| r).collect::<Vec<_>>()), 10_000, TEST_FINAL_CLTV, &logger_a, &scorer, &random_seed_bytes).unwrap();
 
 				let mut payment_preimage = PaymentPreimage([0; 32]);