If Western countries want to ban all face coverings primarily because of real security concerns, then that is obviously not discrimination and is a reasonable thing to do.

If Western countries want to ban all face coverings primarily because of they go against their their social norms, then that is not discrimination but it is slightly illiberal.

If Western countries want to ban all face coverings primarily to stop Muslim women wearing a certain form of clothing, then that is obviously discrimination against a religious group.

It all depends on where you are coming from with your argument.