[S390] Make use of kretprobe_assert.

s390 change for git commit 0f95b7fc

.
That is print kprobes debug data before BUG().

Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Maneesh Soni <maneesh@in.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>