stats: use libosmocore rate counter for in/out_stream.err_ts_counter

The two counters: in_stream.err_ts_counter and out_stream.err_ts_counter
are still handcoded. To make them better accessible they should
be replaced with libosmocore rate counters.

- replace state.in_stream.err_ts_counter with libosmocore rate counter
- replace state.out_stream.err_ts_counter with libosmocore rate counter

Change-Id: I67aa7a8602f60366ef3ba2c5b1319b1b85719f64
Related: OS#2517
diff --git a/tests/mgcp/mgcp_test.c b/tests/mgcp/mgcp_test.c
index f6c421a..0af3799 100644
--- a/tests/mgcp/mgcp_test.c
+++ b/tests/mgcp/mgcp_test.c
@@ -1133,6 +1133,8 @@
 	int last_out_ts_err_cnt = 0;
 	struct mgcp_conn_rtp *conn = NULL;
 	struct mgcp_conn *_conn = NULL;
+	struct rate_ctr test_ctr_in;
+	struct rate_ctr test_ctr_out;
 
 	printf("Testing packet error detection%s%s.\n",
 	       patch_ssrc ? ", patch SSRC" : "",
@@ -1142,6 +1144,11 @@
 	memset(&endp, 0, sizeof(endp));
 	memset(&state, 0, sizeof(state));
 
+	test_ctr_in.current = 0;
+	test_ctr_out.current = 0;
+	state.in_stream.err_ts_ctr = &test_ctr_in;
+	state.out_stream.err_ts_ctr = &test_ctr_out;
+
 	endp.type = &ep_typeset.rtp;
 
 	trunk.vty_number_endpoints = 1;
@@ -1186,18 +1193,18 @@
 		       state.in_stream.last_tsdelta, state.in_stream.last_seq);
 
 		printf("Out TS change: %d, dTS: %d, Seq change: %d, "
-		       "TS Err change: in %+d, out %+d\n",
+		       "TS Err change: in +%lu, out +%lu\n",
 		       state.out_stream.last_timestamp - last_timestamp,
 		       state.out_stream.last_tsdelta,
 		       state.out_stream.last_seq - last_seqno,
-		       state.in_stream.err_ts_counter - last_in_ts_err_cnt,
-		       state.out_stream.err_ts_counter - last_out_ts_err_cnt);
+		       state.in_stream.err_ts_ctr->current - last_in_ts_err_cnt,
+		       state.out_stream.err_ts_ctr->current - last_out_ts_err_cnt);
 
 		printf("Stats: Jitter = %u, Transit = %d\n",
 		       calc_jitter(&state), state.stats.transit);
 
-		last_in_ts_err_cnt = state.in_stream.err_ts_counter;
-		last_out_ts_err_cnt = state.out_stream.err_ts_counter;
+		last_in_ts_err_cnt = state.in_stream.err_ts_ctr->current;
+		last_out_ts_err_cnt = state.out_stream.err_ts_ctr->current;
 		last_timestamp = state.out_stream.last_timestamp;
 		last_seqno = state.out_stream.last_seq;
 	}