Remove logger due to data class

Change-Id: Id08acbb63008a1f80a9c7532b5c3fd08a43655b5
diff --git a/core/api/src/main/java/org/onlab/onos/net/flow/DefaultFlowRule.java b/core/api/src/main/java/org/onlab/onos/net/flow/DefaultFlowRule.java
index 4bbcca1..b175535 100644
--- a/core/api/src/main/java/org/onlab/onos/net/flow/DefaultFlowRule.java
+++ b/core/api/src/main/java/org/onlab/onos/net/flow/DefaultFlowRule.java
@@ -16,7 +16,6 @@
 package org.onlab.onos.net.flow;
 
 import static com.google.common.base.MoreObjects.toStringHelper;
-import static org.slf4j.LoggerFactory.getLogger;
 
 import java.util.Objects;
 
@@ -24,12 +23,9 @@
 import org.onlab.onos.core.DefaultGroupId;
 import org.onlab.onos.core.GroupId;
 import org.onlab.onos.net.DeviceId;
-import org.slf4j.Logger;
 
 public class DefaultFlowRule implements FlowRule {
 
-    private static final Logger log = getLogger(DefaultFlowRule.class);
-
     private final DeviceId deviceId;
     private final int priority;
     private final TrafficSelector selector;