tipc: correct return value of recv_msg routine

Currently, rcv_msg() always returns zero on a packet delivery upcall
from net_device.

To make its behavior more compliant with the way this API should be
used, we change this to let it return NET_RX_SUCCESS (which is zero
anyway) when it is able to handle the packet, and NET_RX_DROP otherwise.
The latter does not imply any functional change, it only enables the
driver to keep more accurate statistics about the fate of delivered
packets.

Signed-off-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/tipc/eth_media.c b/net/tipc/eth_media.c
index c36c938..f80d59f 100644
--- a/net/tipc/eth_media.c
+++ b/net/tipc/eth_media.c
@@ -132,18 +132,18 @@
 
 	if (!net_eq(dev_net(dev), &init_net)) {
 		kfree_skb(buf);
-		return 0;
+		return NET_RX_DROP;
 	}
 
 	if (likely(eb_ptr->bearer)) {
 		if (likely(buf->pkt_type <= PACKET_BROADCAST)) {
 			buf->next = NULL;
 			tipc_recv_msg(buf, eb_ptr->bearer);
-			return 0;
+			return NET_RX_SUCCESS;
 		}
 	}
 	kfree_skb(buf);
-	return 0;
+	return NET_RX_DROP;
 }
 
 /**
diff --git a/net/tipc/ib_media.c b/net/tipc/ib_media.c
index 20b1aa4..c139892 100644
--- a/net/tipc/ib_media.c
+++ b/net/tipc/ib_media.c
@@ -125,18 +125,18 @@
 
 	if (!net_eq(dev_net(dev), &init_net)) {
 		kfree_skb(buf);
-		return 0;
+		return NET_RX_DROP;
 	}
 
 	if (likely(ib_ptr->bearer)) {
 		if (likely(buf->pkt_type <= PACKET_BROADCAST)) {
 			buf->next = NULL;
 			tipc_recv_msg(buf, ib_ptr->bearer);
-			return 0;
+			return NET_RX_SUCCESS;
 		}
 	}
 	kfree_skb(buf);
-	return 0;
+	return NET_RX_DROP;
 }
 
 /**