ACPICA: Harden _PRT repair code; check for minimum package length.

This change prevents a fault during the repair by checking up
front if the _PRT subpackage contains the minimum number of
elements (4).

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

diff --cc drivers/acpi/acpica/nsrepair2.c
Simple merge