Corrected frame counter storing threshold check

Corrected frame counter storing check clause to take frame counter
exhaust into account. If stored frame counter is at maximum do not
initiate storing again.

source/6LoWPAN/ws/ws_pae_controller.c

@@ -1760,9 +1760,12 @@ static void ws_pae_controller_frame_counter_store(pae_controller_t *entry, bool
                 }
                 uint32_t frame_counter = entry->frame_counters.counter[i].frame_counter;
 
-                // If threshold check is disabled or frame counter has advanced for the threshold value, stores the new value
-                if (!use_threshold ||
-                        frame_counter > entry->frame_counters.counter[i].stored_frame_counter + FRAME_COUNTER_STORE_THRESHOLD) {
+                /* If threshold check is disabled or frame counter has advanced for the threshold value, stores the new value.
+                   If frame counter is at maximum at storage, do not initiate storing */
+                if (!use_threshold || (
+                            (frame_counter > entry->frame_counters.counter[i].stored_frame_counter + FRAME_COUNTER_STORE_THRESHOLD) &&
+                            !(entry->frame_counters.counter[i].stored_frame_counter == UINT32_MAX &&
+                              frame_counter >= UINT32_MAX - FRAME_COUNTER_STORE_THRESHOLD))) {
                     entry->frame_counters.counter[i].stored_frame_counter = frame_counter;
                     update_needed = true;
                     tr_debug("Stored updated frame counter: index %i value %"PRIu32"", i, frame_counter);