datapath: Fix compiler warning for HAVE_RHEL7_MAX_MTU.
Fixes: ("datapath: Fix max MTU size on RHEL 7.5 kernel")
@@ -169,7 +169,7 @@ static void do_setup(struct net_device *netdev)
#ifdef HAVE_NET_DEVICE_WITH_MAX_MTU
netdev->max_mtu = ETH_MAX_MTU;
-#elif HAVE_RHEL7_MAX_MTU
+#elif defined(HAVE_RHEL7_MAX_MTU)
netdev->extended->max_mtu = ETH_MAX_MTU;
#endif
netdev->netdev_ops = &internal_dev_netdev_ops;
