Remove `if (pointer == NULL)` after allocations with `new`.

I'm still learning C++.

src/file.cc

@@ -450,10 +450,7 @@ Handle<Value>
 File::New(const Arguments& args)
 {
   HandleScope scope;
-  File *file = new File(args.Holder());
-  if(file == NULL)
-    return Undefined(); // XXX raise error?
-
+  new File(args.Holder());
   return args.This();
 }
 

src/net.cc

@@ -54,9 +54,7 @@ Server::New (const Arguments& args)
   if (args.Length() > 0 && args[0]->IsNumber()) 
     backlog = args[0]->IntegerValue();
 
-  Server *server = new Server(args.Holder(), backlog);
-  if(server == NULL)
-    return Undefined(); // XXX raise error?
+  new Server(args.Holder(), backlog);
 
   return args.This();
 }
@@ -165,9 +163,7 @@ Socket::New(const Arguments& args)
     }
   }
 
-  Socket *s = new Socket(args.Holder(), timeout);
-  if(s == NULL)
-    return Undefined(); // XXX raise error?
+  new Socket(args.Holder(), timeout);
 
   return args.This();
 }

src/timer.cc

@@ -68,9 +68,9 @@ Timer::New (const Arguments& args)
   ev_tstamp after = (double)(args[1]->IntegerValue())  / 1000.0;
   ev_tstamp repeat = (double)(args[2]->IntegerValue())  / 1000.0;
 
-  Timer *timer = new Timer(args.Holder(), callback, after, repeat);
+  new Timer(args.Holder(), callback, after, repeat);
 
-  return scope.Close(timer->handle_);
+  return args.This();
 }
 
 Handle<Value>