[PATCH] mv643xx_eth: Fix ethtool stats

Some stats reported by ethtool -S on mv643xx_eth device are cleared
between each call.  This patch fixes it.
Signed-off-by: NMaxime Bizon <mbizon@freebox.fr>
Signed-off-by: NDale Farnsworth <dale@farnsworth.org>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

drivers/net/mv643xx_eth.c

@@ -2156,7 +2156,7 @@ static void eth_update_mib_counters(struct mv643xx_private *mp)
 	for (offset = ETH_MIB_BAD_OCTETS_RECEIVED;
 			offset <= ETH_MIB_FRAMES_1024_TO_MAX_OCTETS;
 			offset += 4)
-		*(u32 *)((char *)p + offset) = read_mib(mp, offset);
+		*(u32 *)((char *)p + offset) += read_mib(mp, offset);
 
 	p->good_octets_sent += read_mib(mp, ETH_MIB_GOOD_OCTETS_SENT_LOW);
 	p->good_octets_sent +=
@@ -2165,7 +2165,7 @@ static void eth_update_mib_counters(struct mv643xx_private *mp)
 	for (offset = ETH_MIB_GOOD_FRAMES_SENT;
 			offset <= ETH_MIB_LATE_COLLISION;
 			offset += 4)
-		*(u32 *)((char *)p + offset) = read_mib(mp, offset);
+		*(u32 *)((char *)p + offset) += read_mib(mp, offset);
 }
 
 /*