net/mlx4_core: Check port out-of-range before using in mlx4_slave_cap

The range check was performed after using the port number.

Reverse this to prevent a potential array overflow.

Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Reviewed-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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

@@ -485,15 +485,15 @@ static int mlx4_slave_cap(struct mlx4_dev *dev)
 	dev->caps.num_mgms              = 0;
 	dev->caps.num_amgms             = 0;
 
-	for (i = 1; i <= dev->caps.num_ports; ++i)
-		dev->caps.port_mask[i] = dev->caps.port_type[i];
-
 	if (dev->caps.num_ports > MLX4_MAX_PORTS) {
 		mlx4_err(dev, "HCA has %d ports, but we only support %d, "
 			 "aborting.\n", dev->caps.num_ports, MLX4_MAX_PORTS);
 		return -ENODEV;
 	}
 
+	for (i = 1; i <= dev->caps.num_ports; ++i)
+		dev->caps.port_mask[i] = dev->caps.port_type[i];
+
 	if (dev->caps.uar_page_size * (dev->caps.num_uars -
 				       dev->caps.reserved_uars) >
 				       pci_resource_len(dev->pdev, 2)) {