make v2_playbook_on_notify method signatures consistent

This was causing an exception in the TaskQueueManager when a third
party handler plugin was processed that inherited or explicitly
called the callback method from super because the method signature
was incorrect in callback/__init__ and it processed the arguments as
incorrect data types as a side effect.

Signed-off-by: Adam Miller <admiller@redhat.com>
(cherry picked from commit dd9b2c0774)

CHANGELOG.md

@@ -61,8 +61,10 @@ Ansible Changes By Release
 * Be more tolerant about spaces when gathering virtual facts (https://github.com/ansible/ansible/pull/36042)
 * validate add_host name parameter (https://github.com/ansible/ansible/pull/36055)
 * spelling fixes (https://github.com/ansible/ansible/pull/36007)
+* avoid needles vault prompt on ansible-console (https://github.com/ansible/ansible/pull/36244)
+* fix callback function signatures (https://github.com/ansible/ansible/pull/35664)
 
-<a id="2.4.3"></a>
+<a id="2.4.3"></a
 
 ## 2.4.3 "Dancing Days" - 2018-01-31
 

lib/ansible/plugins/callback/__init__.py

@@ -336,8 +336,7 @@ class CallbackBase(AnsiblePlugin):
     def v2_playbook_on_start(self, playbook):
         self.playbook_on_start()
 
-    def v2_playbook_on_notify(self, result, handler):
-        host = result._host.get_name()
+    def v2_playbook_on_notify(self, handler, host):
         self.playbook_on_notify(host, handler)
 
     def v2_playbook_on_no_hosts_matched(self):