net: dlink: fix multicast stats being counted incorrectly

McstFramesRcvdOk counts the number of received multicast packets, and it reports the value correctly.

However, reading McstFramesRcvdOk clears the register to zero. As a result, the driver was reporting only the packets since the last read, instead of the accumulated total.

Fix this by updating the multicast statistics accumulatively instaed of instantaneously.

Tested-on: D-Link DGE-550T Rev-A3

---
Changelog:
v1: https://lore.kernel.org/netdev/[email protected]/
v2: https://lore.kernel.org/netdev/[email protected]/
- Change subject net-next to net.
- Add Fixes: tag.
v3:
- Correct commit reference in Fixes: tag.

---
 drivers/net/ethernet/dlink/dl2k.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

index cc60ee454bf9..6bbf6e5584e5 100644
@@ -1099,7 +1099,7 @@ get_stats (struct net_device *dev)
 	dev->stats.rx_bytes += dr32(OctetRcvOk);
 	dev->stats.tx_bytes += dr32(OctetXmtOk);
 
-	dev->stats.multicast = dr32(McstFramesRcvdOk);
+	dev->stats.multicast += dr32(McstFramesRcvdOk);
 	dev->stats.collisions += dr32(SingleColFrames)
 			     +  dr32(MultiColFrames);
 

2.50.1

Andrew