HID: register debugfs entries before adding device

Register debugfs entries before calling device_add() so debugfs entries are
already present when HID driver's probe function gets called on device hotplug.

Also undo debugfs entry registration if device_add() fails so status
HID_STAT_ADDED and debugfs registration status remain consistent and we don't
leak the debugfs entries.

Signed-off-by: Bruno Prémont <bonbons@linux-vserver.org>
Cc: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

drivers/hid/hid-core.c

@@ -1768,11 +1768,12 @@ int hid_add_device(struct hid_device *hdev)
 	dev_set_name(&hdev->dev, "%04X:%04X:%04X.%04X", hdev->bus,
 		     hdev->vendor, hdev->product, atomic_inc_return(&id));
 
+	hid_debug_register(hdev, dev_name(&hdev->dev));
 	ret = device_add(&hdev->dev);
 	if (!ret)
 		hdev->status |= HID_STAT_ADDED;
-
-	hid_debug_register(hdev, dev_name(&hdev->dev));
+	else
+		hid_debug_unregister(hdev);
 
 	return ret;
 }