ACPICA: iASL,acpi_dump: Improve y/n query

 The y/n query is used for file overwrite. Use fgetc, check for
 standalone newline.

ACPICA commit f9eb60ead76e5b2b6e578b553f592452ccfca47a

Link: https://github.com/acpica/acpica/commit/f9eb60ea


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