update PCA test case

mllib/src/test/scala/org/apache/spark/ml/feature/PCASuite.scala

@@ -66,30 +66,23 @@ class PCASuite extends SparkFunSuite with MLlibTestSparkContext with DefaultRead
     }
   }
 
-  test("PCA read/write") {
-    val t = new PCA()
-      .setInputCol("myInputCol")
-      .setOutputCol("myOutputCol")
-      .setK(3)
-    testDefaultReadWrite(t)
-  }
-
-  test("PCAModel read/write") {
+  test("read/write") {
 
     def checkModelData(model1: PCAModel, model2: PCAModel): Unit = {
       assert(model1.pc === model2.pc)
     }
-
+    val allParams: Map[String, Any] = Map(
+      "k" -> 3,
+      "inputCol" -> "features",
+      "outputCol" -> "pca_features"
+    )
     val data = Seq(
       (0.0, Vectors.sparse(5, Seq((1, 1.0), (3, 7.0)))),
       (1.0, Vectors.dense(2.0, 0.0, 3.0, 4.0, 5.0)),
       (2.0, Vectors.dense(4.0, 0.0, 0.0, 6.0, 7.0))
     )
     val df = sqlContext.createDataFrame(data).toDF("id", "features")
     val pca = new PCA().setK(3)
-    val testParams: Map[String, Any] = Map("k" -> 3, "inputCol" -> "features",
-      "outputCol" -> "pca_features")
-
-    testEstimatorAndModelReadWrite(pca, df, testParams, checkModelData)
+    testEstimatorAndModelReadWrite(pca, df, allParams, checkModelData)
   }
 }