USB: fix __must_check warnings in drivers/usb/misc/

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/usb/misc/cytherm.c b/drivers/usb/misc/cytherm.c
index b20bec4..04e87ac 100644
--- a/drivers/usb/misc/cytherm.c
+++ b/drivers/usb/misc/cytherm.c
@@ -353,7 +353,7 @@
 	dev = kzalloc (sizeof(struct usb_cytherm), GFP_KERNEL);
 	if (dev == NULL) {
 		dev_err (&interface->dev, "Out of memory\n");
-		goto error;
+		goto error_mem;
 	}
 
 	dev->udev = usb_get_dev(udev);
@@ -362,18 +362,35 @@
 
 	dev->brightness = 0xFF;
 
-	device_create_file(&interface->dev, &dev_attr_brightness);   
-	device_create_file(&interface->dev, &dev_attr_temp);
-	device_create_file(&interface->dev, &dev_attr_button);
-	device_create_file(&interface->dev, &dev_attr_port0);
-	device_create_file(&interface->dev, &dev_attr_port1);
+	retval = device_create_file(&interface->dev, &dev_attr_brightness);
+	if (retval)
+		goto error;
+	retval = device_create_file(&interface->dev, &dev_attr_temp);
+	if (retval)
+		goto error;
+	retval = device_create_file(&interface->dev, &dev_attr_button);
+	if (retval)
+		goto error;
+	retval = device_create_file(&interface->dev, &dev_attr_port0);
+	if (retval)
+		goto error;
+	retval = device_create_file(&interface->dev, &dev_attr_port1);
+	if (retval)
+		goto error;
 
-	dev_info (&interface->dev, 
+	dev_info (&interface->dev,
 		  "Cypress thermometer device now attached\n");
 	return 0;
-
- error:
+error:
+	device_remove_file(&interface->dev, &dev_attr_brightness);
+	device_remove_file(&interface->dev, &dev_attr_temp);
+	device_remove_file(&interface->dev, &dev_attr_button);
+	device_remove_file(&interface->dev, &dev_attr_port0);
+	device_remove_file(&interface->dev, &dev_attr_port1);
+	usb_set_intfdata (interface, NULL);
+	usb_put_dev(dev->udev);
 	kfree(dev);
+error_mem:
 	return retval;
 }