Mark netconf related factory as functional interface

- deprecate/remove redundant factory implementations

Change-Id: I29ba9f3397c37c02b37d07dff16a4203186c5fcd
diff --git a/protocols/netconf/ctl/src/main/java/org/onosproject/netconf/ctl/impl/NetconfSessionMinaImpl.java b/protocols/netconf/ctl/src/main/java/org/onosproject/netconf/ctl/impl/NetconfSessionMinaImpl.java
index 31ec0ac..846ec26 100644
--- a/protocols/netconf/ctl/src/main/java/org/onosproject/netconf/ctl/impl/NetconfSessionMinaImpl.java
+++ b/protocols/netconf/ctl/src/main/java/org/onosproject/netconf/ctl/impl/NetconfSessionMinaImpl.java
@@ -199,6 +199,9 @@
     }
 
     private void startClient() throws IOException {
+        log.info("Creating NETCONF session to {}",
+                 deviceInfo.getDeviceId());
+
         client = SshClient.setUpDefaultClient();
         client.getProperties().putIfAbsent(FactoryManager.IDLE_TIMEOUT,
                 TimeUnit.SECONDS.toMillis(idleTimeout));
@@ -1019,6 +1022,10 @@
         }
     }
 
+    /**
+     * @deprecated in 1.14.0
+     */
+    @Deprecated
     public static class MinaSshNetconfSessionFactory implements NetconfSessionFactory {
 
         @Override