Small style fix

core/src/main/scala/spark/metrics/MetricsSystem.scala

@@ -17,7 +17,7 @@
 
 package spark.metrics
 
-import com.codahale.metrics._
+import com.codahale.metrics.{Metric, MetricFilter, MetricRegistry}
 
 import java.util.Properties
 import java.util.concurrent.TimeUnit
@@ -95,7 +95,6 @@ private[spark] class MetricsSystem private (val instance: String) extends Loggin
 
   def removeSource(source: Source) {
     sources -= source
-    println("Removing source: " + source.sourceName)
     registry.removeMatching(new MetricFilter {
       def matches(name: String, metric: Metric): Boolean = name.startsWith(source.sourceName)
     })