USB gadget: gadgetfs dont try to lock before free

I spotted this during my tests with -rt on arm. The -rt patch contains
some better tools
to diagnose problems with locks and some other things...

Original code tries to take semaphore in BUG_ON and then free the memory
with this semaphore.
Signed-off-by: Milan Svoboda <msvoboda@ra.rockwell.com>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/gadget/inode.c

@@ -223,7 +223,6 @@ static void put_ep (struct ep_data *data)
 	/* needs no more cleanup */
 	BUG_ON (!list_empty (&data->epfiles));
 	BUG_ON (waitqueue_active (&data->wait));
-	BUG_ON (down_trylock (&data->lock) != 0);
 	kfree (data);
 }