usb: dwc3: gadget: req->queued must be forced to false in cleanup

I am not sure, why I found it during SG debugging. But, I noticed that
even when req_queued list was empty, there were some request in
request_list having queued flag true. If I run test second time, it
first removes all request from request_list and hence busy_slot was
wrongly incremented.

Cc: <stable@vger.kernel.org>
Signed-off-by: Pratyush Anand <pratyush.anand@st.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

drivers/usb/dwc3/gadget.c

@@ -257,6 +257,7 @@ void dwc3_gadget_giveback(struct dwc3_ep *dep, struct dwc3_request *req,
 				usb_endpoint_xfer_isoc(dep->endpoint.desc))
 				dep->busy_slot++;
 		} while(++i < req->request.num_mapped_sgs);
+		req->queued = false;
 	}
 	list_del(&req->list);
 	req->trb = NULL;