Moved the cca error counter so that it will count even when using radio csma rather then OT csma (#1566)

src/core/mac/mac.cpp

@@ -858,6 +858,11 @@ void Mac::TransmitDoneTask(RadioPacket *aPacket, bool aRxPending, ThreadError aE
         mCounters.mTxErrAbort++;
     }
 
+    if (aError == kThreadError_ChannelAccessFailure)
+    {
+        mCounters.mTxErrCca++;
+    }
+
     if (!RadioSupportsCsmaBackoff() &&
         aError == kThreadError_ChannelAccessFailure &&
         mCsmaAttempts < kMaxCSMABackoffs)
@@ -865,8 +870,6 @@ void Mac::TransmitDoneTask(RadioPacket *aPacket, bool aRxPending, ThreadError aE
         mCsmaAttempts++;
         StartCsmaBackoff();
 
-        mCounters.mTxErrCca++;
-
         ExitNow();
     }