ONOS-2926 Remove IP instead of host when the IP mapping is released

Change-Id: Ifea3366ce8a18ea068e615636b3069e769221c0e
diff --git a/core/net/src/main/java/org/onosproject/net/host/impl/HostManager.java b/core/net/src/main/java/org/onosproject/net/host/impl/HostManager.java
index 43f346b..1473f33 100644
--- a/core/net/src/main/java/org/onosproject/net/host/impl/HostManager.java
+++ b/core/net/src/main/java/org/onosproject/net/host/impl/HostManager.java
@@ -236,6 +236,16 @@
                 post(event);
             }
         }
+
+        @Override
+        public void removeIpFromHost(HostId hostId, IpAddress ipAddress) {
+            checkNotNull(hostId, HOST_ID_NULL);
+            checkValidity();
+            HostEvent event = store.removeIp(hostId, ipAddress);
+            if (event != null) {
+                post(event);
+            }
+        }
     }
 
     // Store delegate to re-post events emitted from the store.