platform/x86: wmi: remove unnecessary checks

The `find_guid_context()` is only called from one place,
and `wblock` and `wdriver` cannot be NULL there.
So remove the currently redundant checks.

Signed-off-by: Barnabás Pőcze <pobrn@protonmail.com>
Link: https://lore.kernel.org/r/20210904175450.156801-11-pobrn@protonmail.com


Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>