ieee802154: fix error handling in ieee802154fake_probe()

commit 8c2dd544 upstream.

In case of any failure ieee802154fake_probe() just calls unregister_netdev().
But it does not look safe to unregister netdevice before it was registered.

The patch implements straightforward resource deallocation in case of
failure in ieee802154fake_probe().

Found by Linux Driver Verification project (linuxtesting.org).
Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>

drivers/net/ieee802154/fakehard.c

@@ -376,17 +376,20 @@ static int ieee802154fake_probe(struct platform_device *pdev)
 
 	err = wpan_phy_register(phy);
 	if (err)
-		goto out;
+		goto err_phy_reg;
 
 	err = register_netdev(dev);
-	if (err < 0)
-		goto out;
+	if (err)
+		goto err_netdev_reg;
 
 	dev_info(&pdev->dev, "Added ieee802154 HardMAC hardware\n");
 	return 0;
 
-out:
-	unregister_netdev(dev);
+err_netdev_reg:
+	wpan_phy_unregister(phy);
+err_phy_reg:
+	free_netdev(dev);
+	wpan_phy_free(phy);
 	return err;
 }