Add FIXME to LinkManager

When multiple provider register Links (e.g., LLDP, Config),
and one of the provider remove a Link, all the Links sharering the
same ConnectionPoint will be removed.

Change-Id: I8e607edd3eeabd849ff8ec9d92367019a42892ac

@@ -214,6 +214,7 @@ public class LinkManager
             checkNotNull(connectPoint, "Connect point cannot be null");
             checkValidity();
             log.info("Links for connection point {} vanished", connectPoint);
+            // FIXME: This will remove links registered by other providers
             removeLinks(getLinks(connectPoint));
         }