##### SUMMARY
If I have a host with a name like `foo` and have variables inside a file `host_vars/foo.yml` inside of a directory properly passed via `--playbook-dir` to the `ansible-inventory` command, vars from that file are not present in the output.

This used to work. The regression was first seen the night of Nov 4, 2019

##### ISSUE TYPE
- Bug Report

##### COMPONENT NAME
lib/ansible/cli/inventory.py

##### ANSIBLE VERSION
```paste below
ansible --version
ansible 2.10.0.dev0
  config file = /Users/alancoding/Documents/repos/jlaska-ansible-playbooks/ansible.cfg
  configured module search path = ['/Users/alancoding/.ansible/plugins/modules', '/usr/share/ansible/plugins/modules']
  ansible python module location = /Users/alancoding/Documents/repos/ansible/lib/ansible
  executable location = /Users/alancoding/.virtualenvs/ansible3/bin/ansible
  python version = 3.6.5 (default, Apr 25 2018, 14:23:58) [GCC 4.2.1 Compatible Apple LLVM 9.1.0 (clang-902.0.39.1)]
```

##### CONFIGURATION
```paste below
$ ansible-config dump --only-changed
DEPRECATION_WARNINGS(/Users/alancoding/Documents/repos/jlaska-ansible-playbooks/ansible.cfg) = False
```

##### OS / ENVIRONMENT
Mac OS


##### STEPS TO REPRODUCE
https://github.com/ansible/test-playbooks/tree/master/inventories

host of interest is `group_one_host_01`

Inventory file: 

```
$ cat inventories/inventory.ini 
ungrouped_host_[01:05]
group_one_host_01 group_one_host_01_has_this_var=True
group_two_host_01 group_two_host_01_has_this_var=True
group_three_host_01 group_three_host_01_has_this_var=True

[group_one]
group_one_host_[01:05]
group_one_and_two_host_[01:05]
group_one_two_and_three_host_[01:05]

[group_one:vars]
is_in_group_one=True
complex_var=[{"dir": "/opt/gwaf/logs", "sourcetype": "gwaf", "something_else": [1, 2, 3]}]

[group_two]
group_two_host_[01:05]
group_one_and_two_host_[01:05]
group_two_and_three_host_[01:05]
group_one_two_and_three_host_[01:05]

[group_two:vars]
is_in_group_two=True

[group_three]
group_three_host_[01:05]
group_two_and_three_host_[01:05]
group_one_two_and_three_host_[01:05]

[group_three:vars]
is_in_group_three=True

[all:vars]
ansible_connection=local
inventories_var=True
```

vars file:

```
$ cat inventories//host_vars/group_one_host_01
group_one_host_01_should_have_this_var: True
```

run:

```
ansible-inventory -i inventories/inventory.ini --list --export --playbook-dir=inventories/ | grep -r "group_one_host_01_should_have_this_var"
```


##### EXPECTED RESULTS
`group_one_host_01_should_have_this_var` should be in the hostvars for `group_one_host_01`


##### ACTUAL RESULTS
The string `group_one_host_01_should_have_this_var` is not seen anywhere in the output.

result = []
        if context.CLIARGS['show_vars']:
            for (name, val) in sorted(dump.items()):
                result.append(InventoryCLI._graph_name('{%s = %s}' % (name, val), depth))
        return result
    @staticmethod
    def _graph_name(name, depth=0):
        if depth:
            name = "  |" * (depth) + "--%s" % name
        return name
    def _graph_group(self, group, depth=0):
        result = [self._graph_name('@%s:' % group.name, depth)]
        depth = depth + 1
        for kid in sorted(group.child_groups, key=attrgetter('name')):
            result.extend(self._graph_group(kid, depth))
        if group.name != 'all':
            for host in sorted(group.hosts, key=attrgetter('name')):
                result.append(self._graph_name(host.name, depth))
                result.extend(self._show_vars(self._get_host_variables(host), depth + 1))
        result.extend(self._show_vars(self._get_group_variables(group), depth))
        return result
    def inventory_graph(self):
        start_at = self._get_group(context.CLIARGS['pattern'])
        if start_at:
            return '\n'.join(self._graph_group(start_at))
        else:
            raise AnsibleOptionsError("Pattern must be valid group name when using --graph")
    def json_inventory(self, top):