hotfix: reserve RBs in Random Access Response case

The RBs were not marked as used. A later UE downlink scheduling
could use those RBs, messing up everything.

Not sure this is the right place to mark them used. Maybe better
to do it in the "if (!CCE_allocation_infeasible" test.

openair2/LAYER2/MAC/eNB_scheduler_RA.c

@@ -114,7 +114,11 @@ void schedule_RA(module_id_t module_idP,frame_t frameP, sub_frame_t subframeP,un
                 RA_template->RA_dci_fmt1,
                 RA_template->RA_dci_size_bits1);
 
-
+          first_rb = 0;
+          vrb_map[first_rb] = 1;
+          vrb_map[first_rb+1] = 1;
+          vrb_map[first_rb+2] = 1;
+          vrb_map[first_rb+3] = 1;
 
           if (PHY_vars_eNB_g[module_idP][CC_id]->frame_parms.frame_type == TDD) {
             switch(PHY_vars_eNB_g[module_idP][CC_id]->frame_parms.N_RB_DL) {