Fixes#9981
Allows a volume which was created by docker (ie, in
/var/lib/docker/vfs/dir) to be used as a Bind argument via the container
start API and overwrite an existing volume.
For example:
```bash
docker create -v /foo --name one
docker create -v /foo --name two
```
This allows the volume from `one` to be passed into the container start
API as a bind to `two`, and it will overwrite it.
This was possible before 7107898d5c
Signed-off-by: Brian Goff <cpuguy83@gmail.com>
49e1ad49c8