Fix clang-tidy modernize-use-nullptr warnings

src/uan/examples/uan-cw-example.cc

@@ -125,7 +125,7 @@ Experiment::ReceivePacket (Ptr<Socket> socket)
     {
       m_bytesTotal += packet->GetSize ();
     }
-  packet = 0;
+  packet = nullptr;
 }
 
 Gnuplot2dDataset
@@ -234,27 +234,27 @@ Experiment::Run (UanHelper &uan)
     uan.EnableAsciiAll (ascii);
 
     Simulator::Run ();
-    sinkNode = 0;
-    sinkSocket = 0;
-    pos = 0;
-    channel = 0;
-    prop = 0;
+    sinkNode = nullptr;
+    sinkSocket = nullptr;
+    pos = nullptr;
+    channel = nullptr;
+    prop = nullptr;
     for (uint32_t i=0; i < nc.GetN (); i++)
       {
-        nc.Get (i) = 0;
+        nc.Get (i) = nullptr;
       }
     for (uint32_t i=0; i < sink.GetN (); i++)
       {
-        sink.Get (i) = 0;
+        sink.Get (i) = nullptr;
       }
 
     for (uint32_t i=0; i < devices.GetN (); i++)
       {
-        devices.Get (i) = 0;
+        devices.Get (i) = nullptr;
       }
     for (uint32_t i=0; i < sinkdev.GetN (); i++)
       {
-        sinkdev.Get (i) = 0;
+        sinkdev.Get (i) = nullptr;
       }
 
     Simulator::Destroy ();
@@ -327,8 +327,8 @@ main (int argc, char **argv)
     }
   gp.GenerateOutput (of);
 
-  per = 0;
-  sinr = 0;
+  per = nullptr;
+  sinr = nullptr;
 
 }