ACPICA: Add a comment, no functional change

ACPICA commit d586c29a026a6172c1113df4d75fd6d764196e77

Describe 2nd byte of the end_tag resource descriptor.

Link: https://github.com/acpica/acpica/commit/d586c29aSigned-off-by: NBob Moore <robert.moore@intel.com>
Signed-off-by: NLv Zheng <lv.zheng@intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/acpi/acpica/utresrc.c

@@ -239,6 +239,13 @@ acpi_ut_walk_aml_resources(struct acpi_walk_state *walk_state,
 				return_ACPI_STATUS(AE_AML_NO_RESOURCE_END_TAG);
 			}
 
+			/*
+			 * Don't attempt to perform any validation on the 2nd byte.
+			 * Although all known ASL compilers insert a zero for the 2nd
+			 * byte, it can also be a checksum (as per the ACPI spec),
+			 * and this is occasionally seen in the field. July 2017.
+			 */
+
 			/* Return the pointer to the end_tag if requested */
 
 			if (!user_function) {