ACPICA: Table Manager: Merge duplicate code (root table)

Merge/remove duplicate code in the root table resize functions
One function is external, the other is internal.  Lv Zheng,

ACPICA BZ 846:
https://acpica.org/bugzilla/show_bug.cgi?id=846



Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>