acer-wmi: fix bitwise bug when set device state

Fix a bitwise bug that was found by Joern Heissler, it must be OR
but not AND when we query current device state.

Acked-by: Joern Heissler <linux-acpi@joern.heissler.de>
Cc: Carlos Corbacho <carlos@strangeworlds.co.uk>
Cc: Matthew Garrett <mjg@redhat.com>
Cc: Dmitry Torokhov <dtor@mail.ru>
Cc: Corentin Chary <corentincj@iksaif.net>
Cc: Thomas Renninger <trenn@suse.de>
Signed-off-by: Lee, Chun-Yi <jlee@novell.com>
Signed-off-by: Matthew Garrett <mjg@redhat.com>