Transceiver: Drop unused rssi_valid struct field

That field is actually never used. Furthermore, if pullRadioVector()
returns false, then the caller should consider the 'trx_ul_burst_ind'
structure as uninitialized. Moreover, RSSI is mandatory - we cannot send
burst indications without it.

Related: OS#4006
Change-Id: Ia109298aebe8ba4750a39338ba7962555903cd82
diff --git a/Transceiver52M/Transceiver.cpp b/Transceiver52M/Transceiver.cpp
index c3896bd..f04a132 100644
--- a/Transceiver52M/Transceiver.cpp
+++ b/Transceiver52M/Transceiver.cpp
@@ -559,7 +559,6 @@
   int max_i = -1;
   signalVector *burst;
   TransceiverState *state = &mStates[chan];
-  bi->rssi_valid = false;
 
   /* Blocking FIFO read */
   radioVector *radio_burst = mReceiveFIFO[chan]->read();
@@ -609,9 +608,6 @@
 
   bi->rssi = 20.0 * log10(rxFullScale / avg);
 
-  /* RSSI estimation are valid */
-  bi->rssi_valid = true;
-
   if (type == IDLE) {
     /* Update noise levels */
     state->mNoises.insert(avg);
diff --git a/Transceiver52M/Transceiver.h b/Transceiver52M/Transceiver.h
index 0f452c1..965d07d 100644
--- a/Transceiver52M/Transceiver.h
+++ b/Transceiver52M/Transceiver.h
@@ -41,7 +41,6 @@
         double rssi; // in dBFS
         double toa;  // in symbols
         double noise; // noise level in dBFS
-        bool rssi_valid; // are RSSI, noise and burstTime valid
 };
 
 class Transceiver;