Use the same coding style in toString() implementations

Change-Id: I116eb140d92b385d36efe120c42cd2fb3efac760
diff --git a/pcep/pcepio/src/main/java/org/onosproject/pcepio/protocol/ver1/PcepLabelUpdateVer1.java b/pcep/pcepio/src/main/java/org/onosproject/pcepio/protocol/ver1/PcepLabelUpdateVer1.java
index 2e6c26b..22fae2b 100644
--- a/pcep/pcepio/src/main/java/org/onosproject/pcepio/protocol/ver1/PcepLabelUpdateVer1.java
+++ b/pcep/pcepio/src/main/java/org/onosproject/pcepio/protocol/ver1/PcepLabelUpdateVer1.java
@@ -33,7 +33,6 @@
 import org.slf4j.LoggerFactory;
 
 import com.google.common.base.MoreObjects;
-import com.google.common.base.MoreObjects.ToStringHelper;
 
 /**
  * Provides PCEP LABEL update .
@@ -348,14 +347,10 @@
 
     @Override
     public String toString() {
-        ToStringHelper toStrHelper = MoreObjects.toStringHelper(getClass());
-
-        if (labelDownload != null) {
-            toStrHelper.add("LabelDownload", labelDownload);
-        }
-        if (labelMap != null) {
-            toStrHelper.add("LabelMap", labelMap);
-        }
-        return toStrHelper.toString();
+        return MoreObjects.toStringHelper(getClass())
+                .omitNullValues()
+                .add("LabelDownload", labelDownload)
+                .add("LabelMap", labelMap)
+                .toString();
     }
 }