usb: chipidea: udc: fix memory leak in _ep_nuke

In hardware_enqueue code adds one extra td with dma_pool_alloc if
mReq->req.zero is true. When _ep_nuke will be called for that endpoint,
dma_pool_free will not be called to free that memory again. That patch
fixes this.

Cc: stable <stable@vger.kernel.org> # v3.5
Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/chipidea/udc.c

@@ -540,6 +540,12 @@ __acquires(mEp->lock)
 		struct ci13xxx_req *mReq = \
 			list_entry(mEp->qh.queue.next,
 				   struct ci13xxx_req, queue);
+
+		if (mReq->zptr) {
+			dma_pool_free(mEp->td_pool, mReq->zptr, mReq->zdma);
+			mReq->zptr = NULL;
+		}
+
 		list_del_init(&mReq->queue);
 		mReq->req.status = -ESHUTDOWN;