IIO: acpi-als: Get rid of ACPICA message printing

Use acpi_evaluation_failure_warn() introduced previously instead of
the ACPICA-specific ACPI_EXCEPTION() macro to log warning messages
regarding ACPI object evaluation failures and drop the
ACPI_MODULE_NAME() definition only used by the ACPICA message
printing macro.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>