Removed unneded changes from wifi

src/devices/wifi/mac-low.cc

@@ -271,7 +271,6 @@ void
 MacLow::DoDispose (void)
 {
   NS_LOG_FUNCTION (this);
-  m_listener = 0;
   CancelAllEvents ();
   m_phy = 0;
   m_stationManager = 0;

src/devices/wifi/qos-utils.cc

@@ -28,23 +28,30 @@ QosUtilsMapTidToAc (uint8_t tid)
   switch (tid) {
   case 0 :
     return AC_BE;
+    break;
   case 1 :
     return AC_BK;
+    break;
   case 2 :
     return AC_BK;
+    break;
   case 3 :
     return AC_BE;
+    break;
   case 4 :
     return AC_VI;
+    break;
   case 5 :
     return AC_VI;
+    break;
   case 6 :
     return AC_VO;
+    break;
   case 7 : 
     return AC_VO;
-  default:
-    return AC_BE;
+    break;
   }
+  return AC_UNDEF;
 }
 
 uint8_t

src/devices/wifi/yans-wifi-phy.cc

@@ -346,7 +346,6 @@ YansWifiPhy::SetReceiveOkCallback (SyncOkCallback callback)
 {
   m_state->SetReceiveOkCallback (callback);
 }
-
 void 
 YansWifiPhy::SetReceiveErrorCallback (SyncErrorCallback callback)
 {