Since most property types do not have a parse property now, this was
broken. Fix it by looking at the setter instead.
Reviewed-by: Anthony Liguori <aliguori@us.ibm.com> Acked-by: Andreas F=E4rber <afaerber@suse.de> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>