s390x/sclp: fix event mask handling

s390x/sclp: fix event mask handling

commit 67915de9f038 ("s390x/event-facility: variable-length event
masks") switched the sclp receive/send mask. This broke the sclp
lm console.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Fixes: commit 67915de9f038 ("s390x/event-facility: variable-length event masks")
Cc: Cornelia Huck <cohuck@redhat.com>
Cc: Jason J. Herne <jjherne@linux.vnet.ibm.com>
Cc: qemu-stable@nongnu.org
Message-Id: <20180202094241.59537-1-borntraeger@de.ibm.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.vnet.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
(cherry picked from commit 869e676ae7c7ef678292652be8995a525e642bee)
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>