net: hso: add failure handler for add_net_device

If the network devices connected to the system beyond
HSO_MAX_NET_DEVICES. add_net_device() in hso_create_net_device()
will be failed for the network_table is full. It will lead to
business failure which rely on network_table, for example,
hso_suspend() and hso_resume(). It will also lead to memory leak
because resource release process can not search the hso_device
object from network_table in hso_free_interface().

Add failure handler for add_net_device() in hso_create_net_device()
to solve the above problems.

Fixes: 72dc1c09 ("HSO: add option hso driver")
Signed-off-by: Ziyang Xuan <william.xuanziyang@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/usb/hso.c

@@ -2535,13 +2535,17 @@ static struct hso_device *hso_create_net_device(struct usb_interface *interface,
 	if (!hso_net->mux_bulk_tx_buf)
 		goto err_free_tx_urb;
 
-	add_net_device(hso_dev);
+	result = add_net_device(hso_dev);
+	if (result) {
+		dev_err(&interface->dev, "Failed to add net device\n");
+		goto err_free_tx_buf;
+	}
 
 	/* registering our net device */
 	result = register_netdev(net);
 	if (result) {
 		dev_err(&interface->dev, "Failed to register device\n");
-		goto err_free_tx_buf;
+		goto err_rmv_ndev;
 	}
 
 	hso_log_port(hso_dev);
@@ -2550,8 +2554,9 @@ static struct hso_device *hso_create_net_device(struct usb_interface *interface,
 
 	return hso_dev;
 
-err_free_tx_buf:
+err_rmv_ndev:
 	remove_net_device(hso_dev);
+err_free_tx_buf:
 	kfree(hso_net->mux_bulk_tx_buf);
 err_free_tx_urb:
 	usb_free_urb(hso_net->mux_bulk_tx_urb);