net/mlx4_en: Count HW buffer overrun only once

commit 281e8b2f upstream.

RdropOvflw counts overrun of HW buffer, therefore should
be used for rx_fifo_errors only.

Currently RdropOvflw counter is mistakenly also set into
rx_missed_errors and rx_over_errors too, which makes the
device total dropped packets accounting to show wrong results.

Fix that. Use it for rx_fifo_errors only.

Fixes: c27a02cd ('mlx4_en: Add driver for Mellanox ConnectX 10GbE NIC')
Signed-off-by: Amir Vadai <amir@vadai.me>
Signed-off-by: Eugenia Emantayev <eugenia@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>

drivers/net/ethernet/mellanox/mlx4/en_port.c

@@ -171,11 +171,11 @@ int mlx4_en_DUMP_ETH_STATS(struct mlx4_en_dev *mdev, u8 port, u8 reset)
 			   be64_to_cpu(mlx4_en_stats->MCAST_novlan);
 	stats->collisions = 0;
 	stats->rx_length_errors = be32_to_cpu(mlx4_en_stats->RdropLength);
-	stats->rx_over_errors = be32_to_cpu(mlx4_en_stats->RdropOvflw);
+	stats->rx_over_errors = 0;
 	stats->rx_crc_errors = be32_to_cpu(mlx4_en_stats->RCRC);
 	stats->rx_frame_errors = 0;
 	stats->rx_fifo_errors = be32_to_cpu(mlx4_en_stats->RdropOvflw);
-	stats->rx_missed_errors = be32_to_cpu(mlx4_en_stats->RdropOvflw);
+	stats->rx_missed_errors = 0;
 	stats->tx_aborted_errors = 0;
 	stats->tx_carrier_errors = 0;
 	stats->tx_fifo_errors = 0;