usb: gadget: dummy_hcd: allow to free requests on disabled endpoints

ep->desc is set to NULL on endpoint disable. That means once an endpoint
is disabled it is not possible to free requests. In my target gadget I
first disable endpoints to make sure I have no requests on the fly and
then free frequests. On dummy I am leaking memory here.
Since I can't imagine a reason why it should be a bad thing, lets allow
to free requests on disabled endpoints. On removal of composite the ep0
request is removed so lets allow that here as well.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Felipe Balbi <balbi@ti.com>

drivers/usb/gadget/dummy_hcd.c

@@ -595,14 +595,12 @@ static struct usb_request *dummy_alloc_request(struct usb_ep *_ep,
 
 static void dummy_free_request(struct usb_ep *_ep, struct usb_request *_req)
 {
-	struct dummy_ep		*ep;
 	struct dummy_request	*req;
 
-	if (!_ep || !_req)
-		return;
-	ep = usb_ep_to_dummy_ep(_ep);
-	if (!ep->desc && _ep->name != ep0name)
+	if (!_ep || !_req) {
+		__WARN();
 		return;
+	}
 
 	req = usb_request_to_dummy_request(_req);
 	WARN_ON(!list_empty(&req->queue));