Changed argument from Device -> DeviceId

- roleChanged(), isReachable()
   Eventually consistent nature of Device store was
  interfering with mastership control.

Change-Id: I9c0dd846a4e30863f922f6706c6cb62fd7c83f29
diff --git a/core/net/src/test/java/org/onlab/onos/net/device/impl/DeviceManagerTest.java b/core/net/src/test/java/org/onlab/onos/net/device/impl/DeviceManagerTest.java
index 79e2f10..d278c24 100644
--- a/core/net/src/test/java/org/onlab/onos/net/device/impl/DeviceManagerTest.java
+++ b/core/net/src/test/java/org/onlab/onos/net/device/impl/DeviceManagerTest.java
@@ -251,7 +251,7 @@
 
 
     private class TestProvider extends AbstractProvider implements DeviceProvider {
-        private Device deviceReceived;
+        private DeviceId deviceReceived;
         private MastershipRole roleReceived;
 
         public TestProvider() {
@@ -263,13 +263,13 @@
         }
 
         @Override
-        public void roleChanged(Device device, MastershipRole newRole) {
+        public void roleChanged(DeviceId device, MastershipRole newRole) {
             deviceReceived = device;
             roleReceived = newRole;
         }
 
         @Override
-        public boolean isReachable(Device device) {
+        public boolean isReachable(DeviceId device) {
             return false;
         }
     }