samples/kprobes: Add s390 case in kprobe example module

Add info prints in sample kprobe handlers for S/390

Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>