usb: dwc3: gadget: giveback request if we can't kick it

There might be situations where a Start Transfer
command might fail, if that ever happens, instead of
simply removing the request from our list, we should
give the request back to the gadget driver,
otherwise we might eventually starve it from requests.
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

drivers/usb/dwc3/gadget.c

@@ -987,7 +987,6 @@ static int __dwc3_gadget_kick_transfer(struct dwc3_ep *dep, u16 cmd_param)
 {
 	struct dwc3_gadget_ep_cmd_params params;
 	struct dwc3_request		*req;
-	struct dwc3			*dwc = dep->dwc;
 	int				starting;
 	int				ret;
 	u32				cmd;
@@ -1020,9 +1019,7 @@ static int __dwc3_gadget_kick_transfer(struct dwc3_ep *dep, u16 cmd_param)
 		 * here and stop, unmap, free and del each of the linked
 		 * requests instead of what we do now.
 		 */
-		usb_gadget_unmap_request(&dwc->gadget, &req->request,
-				req->direction);
-		list_del(&req->list);
+		dwc3_gadget_giveback(dep, req, ret);
 		return ret;
 	}