stats_tcp: fix stats item identifier

The identifier of stats item STATS_TCP_REORD_SEEN is tcp:sndbuf_limited,
it should be tcp:reord_seen.

Change-Id: If3539ceb570ae784cc9b6567c59da7afd11acf82
Related: OS#5701
diff --git a/src/stats_tcp.c b/src/stats_tcp.c
index d2be6a9..dec5b5d 100644
--- a/src/stats_tcp.c
+++ b/src/stats_tcp.c
@@ -83,7 +83,7 @@
 	[STATS_TCP_NOTSENT_BYTES] = { "tcp:notsent_bytes", "bytes not yet sent", "", 60, 0 },
 	[STATS_TCP_RWND_LIMITED] = { "tcp:rwnd_limited", "time (usec) limited by receive window", "", 60, 0 },
 	[STATS_TCP_SNDBUF_LIMITED] = { "tcp:sndbuf_limited", "Time (usec) limited by send buffer", "", 60, 0 },
-	[STATS_TCP_REORD_SEEN] = { "tcp:sndbuf_limited", "reordering events seen", "", 60, 0 },
+	[STATS_TCP_REORD_SEEN] = { "tcp:reord_seen", "reordering events seen", "", 60, 0 },
 };
 
 static struct osmo_stat_item_group_desc stats_tcp_desc = {