fixing stackoverflow

Author: artidoro

src/Microsoft.ML.Recommender/MatrixFactorizationTrainer.cs

@@ -505,7 +505,7 @@ public MatrixFactorizationPredictionTransformer Fit(IDataView trainData, IDataVi
         /// <summary> Trains and returns a <see cref="ITransformer"/>.</summary>
         /// </summary>
         /// <param name="input">The training data set.</param>
-        public MatrixFactorizationPredictionTransformer Fit(IDataView input) => Fit(input);
+        public MatrixFactorizationPredictionTransformer Fit(IDataView input) => Fit(input, null);
 
         /// <summary>
         /// Schema propagation for transformers. Returns the output schema of the data, if

src/Microsoft.ML.StandardLearners/FactorizationMachine/FactorizationMachineTrainer.cs

@@ -513,7 +513,7 @@ public FieldAwareFactorizationMachinePredictionTransformer Fit(IDataView trainDa
         }
 
         /// <summary> Trains and returns a <see cref="ITransformer"/>.</summary>
-        public FieldAwareFactorizationMachinePredictionTransformer Fit(IDataView input) => Fit(input);
+        public FieldAwareFactorizationMachinePredictionTransformer Fit(IDataView input) => Fit(input, null, null);
 
         /// <summary>
         /// Schema propagation for transformers. Returns the output schema of the data, if