Additional ACPI updates for 5.1-rc1

 - Fix a crash caused by unloading an SSDT overlay (Andy Shevchenko).

 - Prevent user space from getting confusing error values on failing
   ACPI sysfs accesses (Rafael Wysocki).

 - Simplify leaf node detection in the PPTT parsing code by using a
   new flag defined in ACPI 6.3 (Jeremy Linton).

 - Add missing "static" in some places in the ACPI configfs code
   (Andy Shevchenko).

 - Fix acpidbg tool path in the ACPI documentation (Flavio Suligoi).
Merge branches 'acpi-tables', 'acpi-debug', 'acpi-doc' and 'acpi-misc'

* acpi-tables:
  ACPI: tables: Simplify PPTT leaf node detection

* acpi-debug:
  ACPI: sysfs: Prevent get_status() from returning acpi_status

* acpi-doc:
  ACPI: Documentation: Fix path for acpidbg tool

* acpi-misc:
  ACPI / configfs: Mark local data structures static
  ACPI / configfs: Mark local functions static