USB: dwc2: hande irq on dead controller correctly

If the controller is dead, the honest answer to the
question whether it has caused an irq is: unknown
As the purpose of the irq return is to trigger switching
off an IRQ, the correct response if you cannot
determine if your device has caused the interrupt is
IRQ_HANDLED
Signed-off-by: Oliver Neukum <oneukum@suse.com>
Link: https://lore.kernel.org/r/20230822112455.18957-1-oneukum@suse.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/dwc2/hcd_intr.c

@@ -2203,11 +2203,13 @@ static void dwc2_hc_intr(struct dwc2_hsotg *hsotg)
 irqreturn_t dwc2_handle_hcd_intr(struct dwc2_hsotg *hsotg)
 {
 	u32 gintsts, dbg_gintsts;
-	irqreturn_t retval = IRQ_NONE;
+	irqreturn_t retval = IRQ_HANDLED;
 
 	if (!dwc2_is_controller_alive(hsotg)) {
 		dev_warn(hsotg->dev, "Controller is dead\n");
 		return retval;
+	} else {
+		retval = IRQ_NONE;
 	}
 
 	spin_lock(&hsotg->lock);