ACPI: fan: Fix error reporting to user space

When user get/set cur_state fails, it should be some negative error
value instead of whatever returned by acpi_evaluate_object() or from
acpi_execute_simple_method(). The return value from these apis is
some positive values greater than 0. For example if AE_NOT_FOUND
is returned it will be "5".

In other ACPI drivers, -ENODEV is returned when ACPI_FAILURE(status)
is true. Do the same thing here for thermal sysfs callbacks for
get and set for failures.

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>