[S390] qdio: prevent call trace if CHPID is offline

If a CHPID is offline during a device shutdown the ccw_device_halt|clear
may fail and the qdio device stays in state STOPPED until the shutdown is
finished. If an interrupt occurs before the device is set to INACTIVE
the STOPPED state triggers a WARN_ON in the interrupt handler.
Prevent this WARN_ON by catching the STOPPED state in the interrupt
handler.

Signed-off-by: Jan Glauber <[e-mail]>
Signed-off-by: Martin Schwidefsky <[e-mail]>

drivers/s390/cio/qdio_main.c

···
 			qdio_handle_activate_check(cdev, intparm, cstat,
 						   dstat);
 		break;
+	case QDIO_IRQ_STATE_STOPPED:
+		break;
 	default:
 		WARN_ON(1);
 	}