fix: resort UE_list after slice multiplexing

- slice multiplexing resorts UE_list for its purposes with restoring the
  original order
- in order to keep the order in UE_list, resort to original order after
  multiplexing
- ideally, this would happen in the multiplexing but currently, the slice_idx
  is not passed to multiplexing (it does not care), so this cannot be done ATM

openair2/LAYER2/MAC/eNB_scheduler_dlsch.c

@@ -744,6 +744,9 @@ schedule_ue_spec(module_id_t module_idP, int slice_idxP,
 
   if (RC.mac[module_idP]->slice_info.interslice_share_active) {
     dlsch_scheduler_interslice_multiplexing(module_idP, frameP, subframeP, eNB->slice_info.rballoc_sub);
+    /* the interslice multiplexing re-sorts the UE_list for the slices it tries
+     * to multiplex, so we need to sort it for the current slice again */
+    sort_UEs(module_idP, slice_idxP, frameP, subframeP);
   }
 
   for (CC_id = 0; CC_id < NFAPI_CC_MAX; CC_id++) {