usb: dwc3: ep0: tidy up Pending Request handling

The way our code was written, we should never have
a DWC3_EP_PENDING_REQUEST flag set out of a Data Phase
and the code in __dwc3_gadget_ep0_queue() did not
reflect that situation properly.

Tidy up that case to avoid any possible mistakes
when starting requests for IRQs which are long
gone.

Cc: stable@vger.kernel.org
Signed-off-by: Felipe Balbi <balbi@ti.com>
diff --git a/drivers/usb/dwc3/ep0.c b/drivers/usb/dwc3/ep0.c
index 2f51de5..74a3828 100644
--- a/drivers/usb/dwc3/ep0.c
+++ b/drivers/usb/dwc3/ep0.c
@@ -149,20 +149,14 @@
 
 		direction = !!(dep->flags & DWC3_EP0_DIR_IN);
 
-		if (dwc->ep0state == EP0_STATUS_PHASE) {
-			type = dwc->three_stage_setup
-				? DWC3_TRBCTL_CONTROL_STATUS3
-				: DWC3_TRBCTL_CONTROL_STATUS2;
-		} else if (dwc->ep0state == EP0_DATA_PHASE) {
-			type = DWC3_TRBCTL_CONTROL_DATA;
-		} else {
-			/* should never happen */
-			WARN_ON(1);
+		if (dwc->ep0state != EP0_DATA_PHASE) {
+			dev_WARN(dwc->dev, "Unexpected pending request\n");
 			return 0;
 		}
 
 		ret = dwc3_ep0_start_trans(dwc, direction,
-				req->request.dma, req->request.length, type);
+				req->request.dma, req->request.length,
+				DWC3_TRBCTL_CONTROL_DATA);
 		dep->flags &= ~(DWC3_EP_PENDING_REQUEST |
 				DWC3_EP0_DIR_IN);
 	} else if (dwc->delayed_status) {