Transceiver: Use already obtained value from Rx msg structure

Change-Id: I3854f284e6d6a561b3816b467985f59e690a282b
diff --git a/Transceiver52M/Transceiver.cpp b/Transceiver52M/Transceiver.cpp
index 56da2e2..d750218 100644
--- a/Transceiver52M/Transceiver.cpp
+++ b/Transceiver52M/Transceiver.cpp
@@ -1062,7 +1062,7 @@
   }
 
   LOGCHAN(chan, DTRXDDL, DEBUG) << "Rx TRXD message (hdr_ver=" << unsigned(dl->common.version)
-    << "): fn=" << fn << ", tn=" << unsigned(dl->common.tn) << ", burst_len=" << burstLen;
+    << "): fn=" << fn << ", tn=" << unsigned(tn) << ", burst_len=" << burstLen;
 
   TransceiverState *state = &mStates[chan];
   GSM::Time currTime = GSM::Time(fn, tn);