ns2: Rename nsi->rate_ctr_idx to nsi->nsvc_rate_ctr_idx

We will soon get another of those indexes.

Change-Id: I68a2ef3b48097f524831dd04821824b21d6d1e18
diff --git a/src/gb/gprs_ns2.c b/src/gb/gprs_ns2.c
index 2dde693..9c9da79 100644
--- a/src/gb/gprs_ns2.c
+++ b/src/gb/gprs_ns2.c
@@ -508,17 +508,17 @@
 	nsvc->sig_weight = 1;
 	nsvc->data_weight = 1;
 
-	nsvc->ctrg = rate_ctr_group_alloc(nsvc, &nsvc_ctrg_desc, bind->nsi->rate_ctr_idx);
+	nsvc->ctrg = rate_ctr_group_alloc(nsvc, &nsvc_ctrg_desc, bind->nsi->nsvc_rate_ctr_idx);
 	if (!nsvc->ctrg) {
 		goto err;
 	}
-	nsvc->statg = osmo_stat_item_group_alloc(nsvc, &nsvc_statg_desc, bind->nsi->rate_ctr_idx);
+	nsvc->statg = osmo_stat_item_group_alloc(nsvc, &nsvc_statg_desc, bind->nsi->nsvc_rate_ctr_idx);
 	if (!nsvc->statg)
 		goto err_group;
 	if (!ns2_vc_fsm_alloc(nsvc, id, initiater))
 		goto err_statg;
 
-	bind->nsi->rate_ctr_idx++;
+	bind->nsi->nsvc_rate_ctr_idx++;
 
 	llist_add(&nsvc->list, &nse->nsvc);
 	llist_add(&nsvc->blist, &bind->nsvc);