acer-wmi: remove useless input argument for internal wmi
acer-wmi: remove useless input argument for internal wmi

The "wmi_interface *iface" is a useless input argument for internal wmi get/set
functions, remove it to clear up source code.

Tested on Lenovo E520.
Tested on Acer TravelMate 4750.

Tested-by: mr.kobzar <06e8e9a80a8ba2e0bfd544d6c5c717a76eac81ee@gmail.com>
Cc: Carlos Corbacho <ab5e2bca84933118bbc9d48ffaccce3bac4eeb64@strangeworlds.co.uk>
Cc: Matthew Garrett <4cf8d479716eba9bc68e0146d95320fcb138b96b@redhat.com>
Cc: Dmitry Torokhov <10a8c465cefc9bdd6c925e26964d23c90f1141cc@mail.ru>
Cc: Corentin Chary <298d22bb5b8e08c296f77ec9e7162462cf47b8a1@iksaif.net>
Cc: Thomas Renninger <dc31099191a1a231a41b126c85d59916cd0f555f@suse.de>
Signed-off-by: Lee, Chun-Yi <1349fcb6a51505700420a1a045f800785baed24b@suse.com>
Signed-off-by: Matthew Garrett <4cf8d479716eba9bc68e0146d95320fcb138b96b@redhat.com>

KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs