net: defxx: Fix missing err handling in dfx_init()

When eisa_driver_register() or tc_register_driver() failed,
the modprobe defxx would fail with some err log as follows:

Error: Driver 'defxx' is already registered, aborting...

Fix this issue by adding err hanling in dfx_init().

Fixes: e89a2cfb7d7b5 ("[TC] defxx: TURBOchannel support")
Signed-off-by: Yongqiang Liu <[e-mail]>
Reviewed-by: Jiri Pirko <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

drivers/net/fddi/defxx.c

···
 	int status;
 
 	status = pci_register_driver(&dfx_pci_driver);
-	if (!status)
-		status = eisa_driver_register(&dfx_eisa_driver);
-	if (!status)
-		status = tc_register_driver(&dfx_tc_driver);
+	if (status)
+		goto err_pci_register;
+
+	status = eisa_driver_register(&dfx_eisa_driver);
+	if (status)
+		goto err_eisa_register;
+
+	status = tc_register_driver(&dfx_tc_driver);
+	if (status)
+		goto err_tc_register;
+
+	return 0;
+
+err_tc_register:
+	eisa_driver_unregister(&dfx_eisa_driver);
+err_eisa_register:
+	pci_unregister_driver(&dfx_pci_driver);
+err_pci_register:
 	return status;
 }