ACPICA: add comments, no functional change

Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Erik Schmauss <erik.schmauss@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/acpi/acpica/exoparg2.c

@@ -287,9 +287,9 @@ acpi_status acpi_ex_opcode_2A_1T_1R(struct acpi_walk_state *walk_state)
 		 * NOTE: A length of zero is ok, and will create a zero-length, null
 		 *       terminated string.
 		 */
-		while ((length < operand[0]->buffer.length) &&
-		       (length < operand[1]->integer.value) &&
-		       (operand[0]->buffer.pointer[length])) {
+		while ((length < operand[0]->buffer.length) &&	/* Length of input buffer */
+		       (length < operand[1]->integer.value) &&	/* Length operand */
+		       (operand[0]->buffer.pointer[length])) {	/* Null terminator */
 			length++;
 		}