Fix analyzer warnings in dart:_vmservice

sdk/lib/vmservice/vmservice.dart

 // Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library dart._vmservice;
 
 import 'dart:async';
 import 'dart:convert';
 import 'dart:isolate';
 import 'dart:typed_data';
@@ skipping 133 matching lines @@
         _exit();
         return;
       }
       if (message.length == 4) {
         // This is a message informing us of the birth or death of an
         // isolate.
         _controlMessageHandler(message[0], message[1], message[2], message[3]);
         return;
       }
     }
-    Logger.root.severe(
-        'Internal vm-service error: ignoring illegal message: $message');
+    print('Internal vm-service error: ignoring illegal message: $message');
   }
 
   void _notSupported(_) {
     throw new UnimplementedError('Service script loading not supported.');
   }
 
   VMService._internal()
       : eventPort = isolateLifecyclePort {
     scriptLoadPort.handler = _notSupported;
     eventPort.handler = messageHandler;
@@ skipping 157 matching lines @@
 }
 
 external void _onStart();
 
 external void _onExit();
 
 external bool _vmListenStream(String streamId);
 
 external void _vmCancelStream(String streamId);