[S390] cio: Trigger verification on device/path not operational.

[S390] cio: Trigger verification on device/path not operational.

Currently, we don't do much on no path or no device situations during
normal user I/O, since we rely on reports regarding those events by
the machine. If we trigger a path verification to bring our device
state up-to-date, we (a) may recover from path failures earlier and
(b) better handle situations where the hardware/hypervisor doesn't
give us enough notifications.

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>