xen-hvm: When using xc_domain_add_to_physmap also include errno when reporting .errors - as it will most likely have the proper error value. Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>