vfio/ccw: update sense data if a unit check is pending

Concurrent-sense data is currently not delivered. This patch stores
the concurrent-sense data to the subchannel if a unit check is pending
and the concurrent-sense bit is enabled. Then a TSCH can retreive the
right IRB data back to the guest.

Acked-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
Message-Id: <20170517004813.58227-13-bjsdjshi@linux.vnet.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
