Include deviceId in Exception message

Change-Id: I1f730c99090bd5078ca24016675208e93ce476bd
diff --git a/core/store/dist/src/main/java/org/onosproject/store/device/impl/DeviceClockManager.java b/core/store/dist/src/main/java/org/onosproject/store/device/impl/DeviceClockManager.java
index ddb45dc..885da07 100644
--- a/core/store/dist/src/main/java/org/onosproject/store/device/impl/DeviceClockManager.java
+++ b/core/store/dist/src/main/java/org/onosproject/store/device/impl/DeviceClockManager.java
@@ -62,7 +62,7 @@
         log.trace("term info for {} is: {}", deviceId, term);
 
         if (term == null) {
-            throw new IllegalStateException("Requesting timestamp for a deviceId without mastership");
+            throw new IllegalStateException("Requesting timestamp for " + deviceId + " without mastership");
         }
         return new MastershipBasedTimestamp(term.termNumber(), ticker.incrementAndGet());
     }