NFC: llcp: Remove the tx backlog queue

Not only it was improperly use to queue backlogged RX skbuffs, but it was
also not processed at all.
If the socket receive queue is full we simply drop the incoming packets.

Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
diff --git a/net/nfc/llcp/llcp.c b/net/nfc/llcp/llcp.c
index 6c59714..003c82f 100644
--- a/net/nfc/llcp/llcp.c
+++ b/net/nfc/llcp/llcp.c
@@ -54,7 +54,6 @@
 
 	skb_queue_purge(&sock->tx_queue);
 	skb_queue_purge(&sock->tx_pending_queue);
-	skb_queue_purge(&sock->tx_backlog_queue);
 
 	if (local == NULL)
 		return;
@@ -785,7 +784,7 @@
 	skb_pull(skb, LLCP_HEADER_SIZE);
 	if (sock_queue_rcv_skb(&llcp_sock->sk, skb)) {
 		pr_err("receive queue is full\n");
-		skb_queue_head(&llcp_sock->tx_backlog_queue, skb);
+		kfree_skb(skb);
 	}
 
 	nfc_llcp_sock_put(llcp_sock);
@@ -980,7 +979,7 @@
 		skb_pull(skb, LLCP_HEADER_SIZE + LLCP_SEQUENCE_SIZE);
 		if (sock_queue_rcv_skb(&llcp_sock->sk, skb)) {
 			pr_err("receive queue is full\n");
-			skb_queue_head(&llcp_sock->tx_backlog_queue, skb);
+			kfree_skb(skb);
 		}
 	}