Fix lints: unnecessary_brace_in_string_interp

pkg/analyzer/lib/task/model.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 analyzer.task.model;
 
 import 'dart:collection';
 import 'dart:developer';
 
 import 'package:analyzer/src/generated/engine.dart' hide AnalysisTask;
@@ skipping 193 matching lines @@
    * this task is expected to produce) or the [caughtException] should be set.
    *
    * Clients may not override this method.
    */
   void perform() {
     try {
       _safelyPerform();
     } on AnalysisException catch (exception, stackTrace) {
       caughtException = new CaughtException(exception, stackTrace);
       AnalysisEngine.instance.logger
-          .logError("Task failed: ${description}", caughtException);
+          .logError("Task failed: $description", caughtException);
     }
   }
 
   @override
   String toString() => description;
 
   /**
    * Given a strongly connected component, find and return a list of
    * [TargetedResult]s that describes a cyclic path within the cycle.  Returns
    * null if no cyclic path is found.
@@ skipping 511 matching lines @@
   /**
    * A work should be done, but without any special urgency.
    */
   NORMAL,
 
   /**
    * Nothing to do.
    */
   NONE
 }