net/mlx4_en: fix off by one in error handling

If an error occurs in mlx4_init_eq_table the index used in the
err_out_unmap label is one too big which results in a panic in
mlx4_free_eq. This patch fixes the index in the error path.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Reviewed-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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

@@ -1305,8 +1305,8 @@ int mlx4_init_eq_table(struct mlx4_dev *dev)
 	return 0;
 
 err_out_unmap:
-	while (i >= 0)
-		mlx4_free_eq(dev, &priv->eq_table.eq[i--]);
+	while (i > 0)
+		mlx4_free_eq(dev, &priv->eq_table.eq[--i]);
 #ifdef CONFIG_RFS_ACCEL
 	for (i = 1; i <= dev->caps.num_ports; i++) {
 		if (mlx4_priv(dev)->port[i].rmap) {