Use qdio buffer helpers to manage the buffers used for the request
and response queues.
No functional change.
Reviewed-by: Steffen Maier <maier@linux.vnet.ibm.com> Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>