libbsc/libmsc: convert old osmo counter into rate_ctrgs

rate counters support the export to statsd and can have a delta value.

Change-Id: Ie749cebd53a0bb618d0e23d375885712078bf8dd
diff --git a/openbsc/src/libbsc/bsc_init.c b/openbsc/src/libbsc/bsc_init.c
index 5c27862..5ea85d0 100644
--- a/openbsc/src/libbsc/bsc_init.c
+++ b/openbsc/src/libbsc/bsc_init.c
@@ -340,9 +340,9 @@
 		LOGP(DLMI, LOGL_ERROR, "Lost some E1 TEI link: %d %p\n", isd->link_type, trx);
 
 		if (isd->link_type == E1INP_SIGN_OML)
-			osmo_counter_inc(trx->bts->network->stats.bts.oml_fail);
+			rate_ctr_inc(&trx->bts->network->ratectrs->ctr[MSC_CTR_BTS_OML_FAIL]);
 		else if (isd->link_type == E1INP_SIGN_RSL)
-			osmo_counter_inc(trx->bts->network->stats.bts.rsl_fail);
+			rate_ctr_inc(&trx->bts->network->ratectrs->ctr[MSC_CTR_BTS_RSL_FAIL]);
 
 		/*
 		 * free all allocated channels. change the nm_state so the