op-node: close p2p sync client

op-node/p2p/node.go

@@ -184,8 +184,11 @@ func (n *NodeP2P) Close() error {
 		if err := n.host.Close(); err != nil {
 			result = multierror.Append(result, fmt.Errorf("failed to close p2p host cleanly: %w", err))
 		}
-		// TODO close sync loop
-
+		if n.syncCl != nil {
+			if err := n.syncCl.Close(); err != nil {
+				result = multierror.Append(result, fmt.Errorf("failed to close p2p sync client cleanly: %w", err))
+			}
+		}
 	}
 	return result.ErrorOrNil()
 }