b552a8c56db8 ("ACPI: remove NID_INVAL") removed the left over uses of
NID_INVAL, but didn't actually remove the definition. Remove it.
Signed-off-by: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Len Brown <len.brown@intel.com>