ACPICA: acpidump: Remove exit() from generic layer to improve portability

This patch removes exit() from generic acpidump code to improve the
portability of this tool. Lv Zheng.

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