[S390] qdio: prevent stack clobber

Don't print more information than fits into the string on the
stack. Combine the informational output of qdio to fit into
one line.

Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>