ACPICA: executer/exsystem: Fix some typo mistakes

ACPICA commit 441747f1dcff770d692acbfd4d85b2cfaabdb38a

Link: https://github.com/acpica/acpica/commit/441747f1


Signed-off-by: Selvarasu Ganesan <selvarasu.ganesan@arm.com>
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>