Fix "Set failed, unreachable, skipped statuses in json plugin"

This change was ineffective because it was modifying the wrong data.
Correct that and add a test.

Change-Id: I26cfba0ff9a3eca05314e12f3f1d66b934c505b6

tests/fixtures/config/job-output/git/common-config/playbooks/job-output.yaml

@@ -1,3 +1,8 @@
 - hosts: all
   tasks:
     - shell: echo "Standard output test {{ zuul.executor.src_root }}"
+    - shell: echo "This should be skipped"
+      when: false
+    - fail:
+        msg: "This should fail"
+      ignore_errors: true

tests/unit/test_v3.py

@@ -4911,6 +4911,7 @@ class TestJobOutput(AnsibleZuulTestCase):
         A = self.fake_gerrit.addFakeChange('org/project', 'master', 'A')
         self.fake_gerrit.addEvent(A.getPatchsetCreatedEvent(1))
         self.waitUntilSettled()
+
         self.assertHistory([
             dict(name='job-output', result='SUCCESS', changes='1,1'),
         ], ordered=False)
@@ -4921,6 +4922,10 @@ class TestJobOutput(AnsibleZuulTestCase):
         self.assertEqual(token,
                          j[0]['plays'][0]['tasks'][0]
                          ['hosts']['localhost']['stdout'])
+        self.assertTrue(j[0]['plays'][0]['tasks'][1]
+                        ['hosts']['localhost']['skipped'])
+        self.assertTrue(j[0]['plays'][0]['tasks'][2]
+                        ['hosts']['localhost']['failed'])
 
         self.log.info(self._get_file(self.history[0],
                                      'work/logs/job-output.txt'))

zuul/ansible/base/callback/zuul_json.py

@@ -158,11 +158,13 @@ class CallbackModule(CallbackBase):
 
     def v2_runner_on_failed(self, result, **kwargs):
         self.v2_runner_on_ok(result, **kwargs)
-        result._host.setdefault('failed', True)
+        self.results[-1]['tasks'][-1]['hosts'][result._host.name].\
+            setdefault('failed', True)
 
     def v2_runner_on_skipped(self, result, **kwargs):
         self.v2_runner_on_ok(result, **kwargs)
-        result._host.setdefault('skipped', True)
+        self.results[-1]['tasks'][-1]['hosts'][result._host.name].\
+            setdefault('skipped', True)
 
     def v2_playbook_on_stats(self, stats):
         """Display info about playbook statistics"""