Clean up SparkKMeans example's code

remove unused code

Author: Raymond Liu <raymond.liu@intel.com>

Closes #1352 from colorant/kmeans and squashes the following commits:

ddcd1dd [Raymond Liu] Clean up SparkKMeans example's code

examples/src/main/scala/org/apache/spark/examples/SparkKMeans.scala

@@ -17,8 +17,6 @@
 
 package org.apache.spark.examples
 
-import java.util.Random
-
 import breeze.linalg.{Vector, DenseVector, squaredDistance}
 
 import org.apache.spark.{SparkConf, SparkContext}
@@ -28,15 +26,12 @@ import org.apache.spark.SparkContext._
  * K-means clustering.
  */
 object SparkKMeans {
-  val R = 1000     // Scaling factor
-  val rand = new Random(42)
 
   def parseVector(line: String): Vector[Double] = {
     DenseVector(line.split(' ').map(_.toDouble))
   }
 
   def closestPoint(p: Vector[Double], centers: Array[Vector[Double]]): Int = {
-    var index = 0
     var bestIndex = 0
     var closest = Double.PositiveInfinity