net: core: dev: replace state xoff flag comparison by netif_xmit_stopped method

Function netif_schedule_queue() has a hardcoded comparison between queue
state and any xoff flag. This comparison does the same thing as method
netif_xmit_stopped(). In terms of code clarity, it is better. See other
methods like: generic_xdp_tx() and dev_direct_xmit().
Signed-off-by: NJulio Faracco <jcfaracco@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/core/dev.c

@@ -2771,7 +2771,7 @@ static struct dev_kfree_skb_cb *get_kfree_skb_cb(const struct sk_buff *skb)
 void netif_schedule_queue(struct netdev_queue *txq)
 {
 	rcu_read_lock();
-	if (!(txq->state & QUEUE_STATE_ANY_XOFF)) {
+	if (!netif_xmit_stopped(txq)) {
 		struct Qdisc *q = rcu_dereference(txq->qdisc);
 
 		__netif_schedule(q);