USB: dummy-hcd: fix "warn-unused-result" messages

This patch (as758) fixes the "warn-unused-result" messages in dummy-hcd.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/gadget/dummy_hcd.c

@@ -816,15 +816,14 @@ usb_gadget_register_driver (struct usb_gadget_driver *driver)
 	dum->gadget.dev.driver = &driver->driver;
 	dev_dbg (udc_dev(dum), "binding gadget driver '%s'\n",
 			driver->driver.name);
-	if ((retval = driver->bind (&dum->gadget)) != 0) {
-		dum->driver = NULL;
-		dum->gadget.dev.driver = NULL;
-		return retval;
-	}
+	if ((retval = driver->bind (&dum->gadget)) != 0)
+		goto err_bind_gadget;
 
 	driver->driver.bus = dum->gadget.dev.parent->bus;
-	driver_register (&driver->driver);
-	device_bind_driver (&dum->gadget.dev);
+	if ((retval = driver_register (&driver->driver)) != 0)
+		goto err_register;
+	if ((retval = device_bind_driver (&dum->gadget.dev)) != 0)
+		goto err_bind_driver;
 
 	/* khubd will enumerate this in a while */
 	spin_lock_irq (&dum->lock);
@@ -834,6 +833,19 @@ usb_gadget_register_driver (struct usb_gadget_driver *driver)
 
 	usb_hcd_poll_rh_status (dummy_to_hcd (dum));
 	return 0;
+
+err_bind_driver:
+	driver_unregister (&driver->driver);
+err_register:
+	driver->unbind (&dum->gadget);
+	spin_lock_irq (&dum->lock);
+	dum->pullup = 0;
+	set_link_state (dum);
+	spin_unlock_irq (&dum->lock);
+err_bind_gadget:
+	dum->driver = NULL;
+	dum->gadget.dev.driver = NULL;
+	return retval;
 }
 EXPORT_SYMBOL (usb_gadget_register_driver);
 
@@ -916,7 +928,9 @@ static int dummy_udc_probe (struct platform_device *pdev)
 	usb_get_hcd (dummy_to_hcd (dum));
 
 	platform_set_drvdata (pdev, dum);
-	device_create_file (&dum->gadget.dev, &dev_attr_function);
+	rc = device_create_file (&dum->gadget.dev, &dev_attr_function);
+	if (rc < 0)
+		device_unregister (&dum->gadget.dev);
 	return rc;
 }
 
@@ -1864,8 +1878,7 @@ static int dummy_start (struct usb_hcd *hcd)
 #endif
 
 	/* FIXME 'urbs' should be a per-device thing, maybe in usbcore */
-	device_create_file (dummy_dev(dum), &dev_attr_urbs);
-	return 0;
+	return device_create_file (dummy_dev(dum), &dev_attr_urbs);
 }
 
 static void dummy_stop (struct usb_hcd *hcd)