remove a unused global storage of slot number

This has no meaning at a global level, we run several slots: one tx,
several rx at same time. Some minor cleaning of C style

openair1/SCHED_NR/fapi_nr_l1.c

@@ -159,8 +159,7 @@ void nr_schedule_response(NR_Sched_Rsp_t *Sched_INFO)
 
   if (NFAPI_MODE == NFAPI_MONOLITHIC){
     if (slot_type == NR_DOWNLINK_SLOT || slot_type == NR_MIXED_SLOT) {
-      processingData_L1tx_t *msgTx=NULL;
-      msgTx = gNB->msgDataTx;
+      processingData_L1tx_t *msgTx = gNB->msgDataTx;
       msgTx->num_pdsch_slot = 0;
       msgTx->num_dl_pdcch = 0;
       msgTx->num_ul_pdcch = number_ul_dci_pdu;