usb: dwc3: gadget: Check for in-progress END_TRANSFER

While handling TRBs completion, if a END_TRANSFER command isn't
completed, don't kick new transfer or issue END_TRANSFER command.
Signed-off-by: Thinh Nguyen <thinhn@synopsys.com>
Signed-off-by: Felipe Balbi <balbi@kernel.org>

drivers/usb/dwc3/gadget.c

@@ -2675,11 +2675,15 @@ static void dwc3_gadget_endpoint_transfer_in_progress(struct dwc3_ep *dep,
 
 	dwc3_gadget_ep_cleanup_completed_requests(dep, event, status);
 
+	if (dep->flags & DWC3_EP_END_TRANSFER_PENDING)
+		goto out;
+
 	if (stop)
 		dwc3_stop_active_transfer(dep, true, true);
 	else if (dwc3_gadget_ep_should_continue(dep))
 		__dwc3_gadget_kick_transfer(dep);
 
+out:
 	/*
 	 * WORKAROUND: This is the 2nd half of U1/U2 -> U0 workaround.
 	 * See dwc3_gadget_linksts_change_interrupt() for 1st half.