bridge: 64bit rx/tx counters

Use u64_stats_sync infrastructure to provide 64bit rx/tx
counters even on 32bit hosts.

It is safe to use a single u64_stats_sync for rx and tx,
because BH is disabled on both, and we use per_cpu data.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index 07cf57b..3f0678f 100644
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -16,6 +16,7 @@
 #include <linux/netdevice.h>
 #include <linux/if_bridge.h>
 #include <linux/netpoll.h>
+#include <linux/u64_stats_sync.h>
 #include <net/route.h>
 
 #define BR_HASH_BITS 8
@@ -156,10 +157,11 @@
 #define br_port_exists(dev) (dev->priv_flags & IFF_BRIDGE_PORT)
 
 struct br_cpu_netstats {
-	unsigned long	rx_packets;
-	unsigned long	rx_bytes;
-	unsigned long	tx_packets;
-	unsigned long	tx_bytes;
+	u64			rx_packets;
+	u64			rx_bytes;
+	u64			tx_packets;
+	u64			tx_bytes;
+	struct u64_stats_sync	syncp;
 };
 
 struct net_bridge