[NET]: Make and use skb_get_queue_mapping

Make the helper for getting the field, symmetrical to
the "set" one. Return 0 if CONFIG_NETDEVICES_MULTIQUEUE=n
Signed-off-by: NPavel Emelyanov <xemul@openvz.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/cpmac.c

@@ -471,7 +471,7 @@ static int cpmac_start_xmit(struct sk_buff *skb, struct net_device *dev)
 	}
 
 	len = max(skb->len, ETH_ZLEN);
-	queue = skb->queue_mapping;
+	queue = skb_get_queue_mapping(skb);
 #ifdef CONFIG_NETDEVICES_MULTIQUEUE
 	netif_stop_subqueue(dev, queue);
 #else

include/linux/skbuff.h

@@ -1769,6 +1769,15 @@ static inline void skb_set_queue_mapping(struct sk_buff *skb, u16 queue_mapping)
 #endif
 }
 
+static inline u16 skb_get_queue_mapping(struct sk_buff *skb)
+{
+#ifdef CONFIG_NETDEVICES_MULTIQUEUE
+	return skb->queue_mapping;
+#else
+	return 0;
+#endif
+}
+
 static inline void skb_copy_queue_mapping(struct sk_buff *to, const struct sk_buff *from)
 {
 #ifdef CONFIG_NETDEVICES_MULTIQUEUE

net/sched/sch_teql.c

@@ -266,7 +266,7 @@ static int teql_master_xmit(struct sk_buff *skb, struct net_device *dev)
 	int busy;
 	int nores;
 	int len = skb->len;
-	int subq = skb->queue_mapping;
+	int subq = skb_get_queue_mapping(skb);
 	struct sk_buff *skb_res = NULL;
 
 	start = master->slaves;