ACPI: thermal: Remove redundant acpi_has_method() calls

The following acpi_has_method() calls are unnecessary since
acpi_execute_simple_method() and acpi_evaluate_reference() will
return an error if the given method does not exist.

Remove acpi_has_method() calls to avoid additional work.

Signed-off-by: Kelsey Skunberg <skunberg.kelsey@gmail.com>
[ rjw: Subject ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>