usb: dwc3: drd: Don't free non-existing irq

If the driver is configured to use DRD role-switch, it's not OTG. There
won't be OTG irq to free. Check for dwc->otg_irq before freeing it.
Signed-off-by: Thinh Nguyen <thinhn@synopsys.com>
Signed-off-by: Felipe Balbi <balbi@kernel.org>

drivers/usb/dwc3/drd.c

@@ -653,6 +653,6 @@ void dwc3_drd_exit(struct dwc3 *dwc)
 		break;
 	}
 
-	if (!dwc->edev)
+	if (dwc->otg_irq)
 		free_irq(dwc->otg_irq, dwc);
 }