##### 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.

from ansible.vars.plugins import get_vars_from_inventory_sources
display = Display()
INTERNAL_VARS = frozenset(['ansible_diff_mode',
                           'ansible_facts',
                           'ansible_forks',
                           'ansible_inventory_sources',
                           'ansible_limit',
                           'ansible_playbook_python',
                           'ansible_run_tags',
                           'ansible_skip_tags',
                           'ansible_verbosity',
                           'ansible_version',
                           'inventory_dir',
                           'inventory_file',
                           'inventory_hostname',
                           'inventory_hostname_short',
                           'groups',
                           'group_names',
                           'omit',
                           'playbook_dir', ])
class InventoryCLI(CLI):
    ''' used to display or dump the configured inventory as Ansible sees it '''
    ARGUMENTS = {'host': 'The name of a host to match in the inventory, relevant when using --list',
                 'group': 'The name of a group in the inventory, relevant when using --graph', }
    def __init__(self, args):
        super(InventoryCLI, self).__init__(args)
        self.vm = None
        self.loader = None
        self.inventory = None
    def init_parser(self):