net: ethernet: ixgbe: check the return value of ixgbe_mii_bus_init()

This function may fail. Check its return value and propagate the error
code.
Signed-off-by: NBartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/intel/ixgbe/ixgbe_main.c

@@ -11173,10 +11173,14 @@ static int ixgbe_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 			IXGBE_LINK_SPEED_10GB_FULL | IXGBE_LINK_SPEED_1GB_FULL,
 			true);
 
-	ixgbe_mii_bus_init(hw);
+	err = ixgbe_mii_bus_init(hw);
+	if (err)
+		goto err_netdev;
 
 	return 0;
 
+err_netdev:
+	unregister_netdev(netdev);
 err_register:
 	ixgbe_release_hw_control(adapter);
 	ixgbe_clear_interrupt_scheme(adapter);