KVM: s390: Fix sdnxo setting for nested guests

If the guest does not use the host register management, but it uses
the sdnx area, we must fill in a proper sdnxo value (address of sdnx
and the sdnxc).

Reported-by: David Hildenbrand <[e-mail]>
Signed-off-by: Christian Borntraeger <[e-mail]>
Acked-by: Cornelia Huck <[e-mail]>

arch/s390/kvm/vsie.c

···
 			rc = set_validity_icpt(scb_s, 0x10b0U);
 		if (rc)
 			goto unpin;
-		scb_s->sdnxo = hpa;
+		scb_s->sdnxo = hpa | sdnxc;
 	}
 	return 0;
 unpin: