wifi: remove useless ctor in BlockAckManager::Item

src/wifi/model/block-ack-manager.cc

@@ -29,11 +29,6 @@ namespace ns3 {
 
 NS_LOG_COMPONENT_DEFINE ("BlockAckManager");
 
-BlockAckManager::Item::Item ()
-{
-  NS_LOG_FUNCTION (this);
-}
-
 BlockAckManager::Item::Item (Ptr<const Packet> packet, const WifiMacHeader &hdr, Time tStamp)
   : packet (packet),
     hdr (hdr),
@@ -138,7 +133,7 @@ BlockAckManager::CreateAgreement (const MgtAddBaRequestHeader *reqHdr, Mac48Addr
       agreement.SetDelayedBlockAck ();
     }
   agreement.SetState (OriginatorBlockAckAgreement::PENDING);
-  PacketQueue queue (0);
+  PacketQueue queue;
   std::pair<OriginatorBlockAckAgreement, PacketQueue> value (agreement, queue);
   m_agreements.insert (std::make_pair (key, value));
   m_blockPackets (recipient, reqHdr->GetTid ());

src/wifi/model/block-ack-manager.h

@@ -442,7 +442,6 @@ private:
    */
   struct Item
   {
-    Item ();
     /**
      * Constructor
      *