Fix trackback on providing arguemnt --all to ansible-doc command (#52034)

* Remove redundant argument from the function caller
* Add unit test
* Add changelog

changelogs/fragments/52034-fix-traceback-on_ansible-doc_-all.yaml

@@ -0,0 +1,2 @@
+bugfixes:
+  - ansible-doc - Fix traceback on providing arguemnt --all to ansible-doc command

lib/ansible/cli/doc.py

@@ -117,7 +117,7 @@ class DocCLI(CLI):
 
         # process all plugins of type
         if self.options.all_plugins:
-            self.args = self.get_all_plugins_of_type(plugin_type, loader)
+            self.args = self.get_all_plugins_of_type(plugin_type)
 
         # dump plugin metadata as JSON
         if self.options.json_dump:

test/units/cli/test_doc.py

@@ -0,0 +1,12 @@
+# Copyright: (c) 2019, Ansible Project
+# GNU General Public License v3.0+ (see COPYING or https://www.gnu.org/licenses/gpl-3.0.txt)
+
+from __future__ import (absolute_import, division, print_function)
+__metaclass__ = type
+
+from ansible.cli.doc import DocCLI
+
+
+def test_parsing_all_option():
+    doc_cli = DocCLI(['/n/ansible-doc', '-a'])
+    doc_cli.parse()