net_dma: simple removal

Per commit "77873803363c net_dma: mark broken" net_dma is no longer used
and there is no plan to fix it.

This is the mechanical removal of bits in CONFIG_NET_DMA ifdef guards.
Reverting the remainder of the net_dma induced changes is deferred to
subsequent patches.

Marked for stable due to Roman's report of a memory leak in
dma_pin_iovec_pages():

    https://lkml.org/lkml/2014/9/3/177

Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Vinod Koul <vinod.koul@intel.com>
Cc: David Whipple <whipple@securedatainnovations.ch>
Cc: Alexander Duyck <alexander.h.duyck@intel.com>
Cc: <stable@vger.kernel.org>
Reported-by: Roman Gushchin <klamm@yandex-team.ru>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
diff --git a/include/net/sock.h b/include/net/sock.h
index b9586a13..3353b47 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -231,7 +231,6 @@
   *	@sk_receive_queue: incoming packets
   *	@sk_wmem_alloc: transmit queue bytes committed
   *	@sk_write_queue: Packet sending queue
-  *	@sk_async_wait_queue: DMA copied packets
   *	@sk_omem_alloc: "o" is "option" or "other"
   *	@sk_wmem_queued: persistent queue size
   *	@sk_forward_alloc: space allocated forward
@@ -354,10 +353,6 @@
 	struct sk_filter __rcu	*sk_filter;
 	struct socket_wq __rcu	*sk_wq;
 
-#ifdef CONFIG_NET_DMA
-	struct sk_buff_head	sk_async_wait_queue;
-#endif
-
 #ifdef CONFIG_XFRM
 	struct xfrm_policy	*sk_policy[2];
 #endif
@@ -2214,27 +2209,15 @@
  * sk_eat_skb - Release a skb if it is no longer needed
  * @sk: socket to eat this skb from
  * @skb: socket buffer to eat
- * @copied_early: flag indicating whether DMA operations copied this data early
  *
  * This routine must be called with interrupts disabled or with the socket
  * locked so that the sk_buff queue operation is ok.
 */
-#ifdef CONFIG_NET_DMA
-static inline void sk_eat_skb(struct sock *sk, struct sk_buff *skb, bool copied_early)
-{
-	__skb_unlink(skb, &sk->sk_receive_queue);
-	if (!copied_early)
-		__kfree_skb(skb);
-	else
-		__skb_queue_tail(&sk->sk_async_wait_queue, skb);
-}
-#else
-static inline void sk_eat_skb(struct sock *sk, struct sk_buff *skb, bool copied_early)
+static inline void sk_eat_skb(struct sock *sk, struct sk_buff *skb)
 {
 	__skb_unlink(skb, &sk->sk_receive_queue);
 	__kfree_skb(skb);
 }
-#endif
 
 static inline
 struct net *sock_net(const struct sock *sk)