Replaced MacCtx.NvmCtx->AckTimeoutRetry with MacCtx.AckTimeoutRetry

Author: mluis1

src/mac/LoRaMac.c

@@ -2540,7 +2540,7 @@ static void ResetMacParameters( void )
     MacCtx.ChannelsNbTransCounter = 0;
     MacCtx.AckTimeoutRetries = 1;
     MacCtx.AckTimeoutRetriesCounter = 1;
-    MacCtx.NvmCtx->AckTimeoutRetry = false;
+    MacCtx.AckTimeoutRetry = false;
 
     MacCtx.NvmCtx->MaxDCycle = 0;
     MacCtx.NvmCtx->AggregatedDCycle = 1;
@@ -2963,7 +2963,7 @@ static bool StopRetransmission( void )
 
     MacCtx.ChannelsNbTransCounter = 0;
     MacCtx.NodeAckRequested = false;
-    MacCtx.NvmCtx->AckTimeoutRetry = false;
+    MacCtx.AckTimeoutRetry = false;
     MacCtx.MacState &= ~LORAMAC_TX_RUNNING;
 
     return true;