s390/cio: make use of newly added format 1 channel-path data

Make use of the stored copy of format 1 channel-path data instead
of querying the information every time the corresponding function
is called.

Reviewed-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>