Xext: selinux: use static reply struct init on declaration

Make the code a bit easier to read by using initialization of the reply structs, at the point of declaration. Most of them aren't written to later, just passed into WriteReplyToClient(). Also dropping some useless zero assignments (struct initializers automatically zero-out unmentioned fields).

Signed-off-by: Enrico Weigelt, metux IT consult info@metux.net