[S390] lost interrupt after chpid vary off/on cycle.

I/O on a CCW device may stall if a channel path to that device is
logicaly varied off/on. A user I/O interrupt can get misinterpreted
as interrupt for an internal path verification operation due to a
missing check and is therefore never reported to the device driver.

Correct check for pending interruptions before starting path
verification.
Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

drivers/s390/cio/device_fsm.c

@@ -772,6 +772,7 @@ ccw_device_online_verify(struct ccw_device *cdev, enum dev_event dev_event)
 	stsch(sch->schid, &sch->schib);
 
 	if (sch->schib.scsw.actl != 0 ||
+	    (sch->schib.scsw.stctl & SCSW_STCTL_STATUS_PEND) ||
 	    (cdev->private->irb.scsw.stctl & SCSW_STCTL_STATUS_PEND)) {
 		/*
 		 * No final status yet or final status not yet delivered