Exit signal cleanup: pass in references, make the receiver clone as needed

core/src/thin_client.rs

@@ -394,13 +394,8 @@ pub fn poll_gossip_for_leader(leader_gossip: SocketAddr, timeout: Option<u64>) -
     let (node, gossip_socket) = ClusterInfo::spy_node();
     let my_addr = gossip_socket.local_addr().unwrap();
     let cluster_info = Arc::new(RwLock::new(ClusterInfo::new(node)));
-    let gossip_service = GossipService::new(
-        &cluster_info.clone(),
-        None,
-        None,
-        gossip_socket,
-        exit.clone(),
-    );
+    let gossip_service =
+        GossipService::new(&cluster_info.clone(), None, None, gossip_socket, &exit);
 
     let leader_entry_point = NodeInfo::new_entry_point(&leader_gossip);
     cluster_info