s390x/kvm: helper to set the SIGP status in SigpInfo

s390x/kvm: helper to set the SIGP status in SigpInfo

Whenever we set the SIGP status in the status register, we have to wipe out
the lower 4 bytes and keep the higher 4 bytes. Also the condition code will
always be set to STATUS_STORED.

Let's introduce the wrapper for SigpInfo, as this will avoid most duplicate
code in the future.

Reviewed-by: Thomas Huth <[email protected]>
Reviewed-by: Cornelia Huck <[email protected]>
Signed-off-by: Jens Freimann <[email protected]>
Signed-off-by: David Hildenbrand <[email protected]>
Message-Id: <1424783731[email protected]>
Signed-off-by: Christian Borntraeger <[email protected]>