net: sched: fix typo in net_device ifdef

This should have been #ifdef not #if.
Reported-by: NFengguang Wu <fengguang.wu@intel.com>
Fixes: d2788d34 ("net: sched: further simplify handle_ing")
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

include/linux/netdevice.h

@@ -1655,7 +1655,7 @@ struct net_device {
 	rx_handler_func_t __rcu	*rx_handler;
 	void __rcu		*rx_handler_data;
 
-#if CONFIG_NET_CLS_ACT
+#ifdef CONFIG_NET_CLS_ACT
 	struct tcf_proto __rcu  *ingress_cl_list;
 #endif
 	struct netdev_queue __rcu *ingress_queue;