HID: roccat: check cdev_add return value

Return value of cdev_add in hid_roccat.c init was not checked.
Signed-off-by: Michael Rissi <michael.rissi@dectris.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

drivers/hid/hid-roccat.c

@@ -366,7 +366,7 @@ void roccat_disconnect(int minor)
 	mutex_lock(&devices_lock);
 	devices[minor] = NULL;
 	mutex_unlock(&devices_lock);
-	
+
 	if (device->open) {
 		hid_hw_close(device->hid);
 		wake_up_interruptible(&device->wait);
@@ -426,13 +426,23 @@ static int __init roccat_init(void)
 
 	if (retval < 0) {
 		pr_warn("can't get major number\n");
-		return retval;
+		goto error;
 	}
 
 	cdev_init(&roccat_cdev, &roccat_ops);
-	cdev_add(&roccat_cdev, dev_id, ROCCAT_MAX_DEVICES);
+	retval = cdev_add(&roccat_cdev, dev_id, ROCCAT_MAX_DEVICES);
 
+	if (retval < 0) {
+		pr_warn("cannot add cdev\n");
+		goto cleanup_alloc_chrdev_region;
+	}
 	return 0;
+
+
+ cleanup_alloc_chrdev_region:
+	unregister_chrdev_region(dev_id, ROCCAT_MAX_DEVICES);
+ error:
+	return retval;
 }
 
 static void __exit roccat_exit(void)