UPSTREAM: ACPI: thermal: drop an always true check

Address of a field inside a struct can't possibly be null; gcc-12 warns
about this.

Signed-off-by: Adam Borowski <kilobyte@angband.pl>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Bug: 199872592
(cherry picked from commit e5b5d254)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: Iee5ef7f4009dbcc13ce15c51b35d5f1dde7f7a30