remove the trailing <vm> parameter.

You can do the same thing with `--vm=`

```
$ ./boot2docker-cli-v0.8.0-linux-amd64 --vm=d2d status baz
running
$ ./boot2docker-cli-v0.8.0-linux-amd64 --vm=bar status d2d
2014/05/09 12:10:40 Failed to get machine "bar": machine does not exist
```