ACPICA: Improve warning message for "invalid ACPI name"

ACPICA commit 91bef8bea9cd69c33447ba1bfe2c4273994500fd

Added an underscore instead of an (illegal) *

Link: https://github.com/acpica/acpica/commit/91bef8be


Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>