Input: wistron - fix setting up special buttons

If either wifi or bluetooth button has been detected, the code
would break off the loop. But there are laptops that have both
types of buttons, so the loop has to continue checking.

Signed-off-by: Reiner Herrmann <reiner@reiner-h.de>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>