Remove stale line of code from test. (dotnet#297)

Author: codemzs

test/Microsoft.ML.Tests/Scenarios/SentimentPredictionTests.cs

@@ -27,7 +27,7 @@ public void TrainAndPredictSentimentModelTest()
             var model = pipeline.Train<SentimentData, SentimentPrediction>();
             var testData = PrepareTextLoaderTestData();
             var evaluator = new BinaryClassificationEvaluator();
-            BinaryClassificationMetrics metrics = evaluator.Evaluate(model, testData);
+            var metrics = evaluator.Evaluate(model, testData);
             ValidateExamples(model);
             ValidateBinaryMetrics(metrics);
         }
@@ -36,7 +36,6 @@ public void TrainAndPredictSentimentModelTest()
         public void TrainTestPredictSentimentModelTest()
         {
             var pipeline = PreparePipeline();
-            PredictionModel<SentimentData, SentimentPrediction> model = pipeline.Train<SentimentData, SentimentPrediction>();
             var testData = PrepareTextLoaderTestData();
             var tt = new TrainTestEvaluator().TrainTestEvaluate<SentimentData, SentimentPrediction>(pipeline, testData);