ACPICA: Eliminate some small unnecessary pathname functions.

Removed several small pathname functions to increase efficiency.
Essentially, they replace a function call with a single compare.

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>