Revert "s390/ism: fix receive message buffer allocation"

This reverts commit 58effa34

.
Review was not finished on this patch. So it's not ready for
upstreaming.

Signed-off-by: Gerd Bayer <gbayer@linux.ibm.com>
Link: https://lore.kernel.org/r/20240409113753.21813684-1-gbayer@linux.ibm.com
Fixes: 58effa34

 ("s390/ism: fix receive message buffer allocation")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>