KVM: s390: ENOTSUPP -> EOPNOTSUPP fixups

There is no ENOTSUPP for userspace.

Reported-by: Julian Wiedmann <jwi@linux.ibm.com>
Fixes: 51978393 ("KVM: s390: introduce ais mode modify function")
Fixes: 2c1a48f2

 ("KVM: S390: add new group for flic")
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>