tipc: refactor function filter_rcv()

In the following commits we will need to handle multiple incoming and
rejected/returned buffers in the function socket.c::filter_rcv().
As a preparation for this, we generalize the function by handling
buffer queues instead of individual buffers. We also introduce a
help function tipc_skb_reject(), and rename filter_rcv() to
tipc_sk_filter_rcv() in line with other functions in socket.c.

Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/tipc/msg.c b/net/tipc/msg.c
index 17146c1..1649d45 100644
--- a/net/tipc/msg.c
+++ b/net/tipc/msg.c
@@ -666,3 +666,10 @@ void __tipc_skb_queue_sorted(struct sk_buff_head *list, u16 seqno,
 	}
 	kfree_skb(skb);
 }
+
+void tipc_skb_reject(struct net *net, int err, struct sk_buff *skb,
+		     struct sk_buff_head *xmitq)
+{
+	if (tipc_msg_reverse(tipc_own_addr(net), &skb, err))
+		__skb_queue_tail(xmitq, skb);
+}