fix(repo.sls): fix `salt-lint` errors

```bash
Examining php/hhvm/repo.sls of type state
[206] Jinja variables should have spaces before and after: {{ var_name }}
php/hhvm/repo.sls:12
    - name: deb http://dl.hhvm.com/{{ salt['grains.get']('os')|lower }} {{ salt['grains.get']('oscodename')}} main
```

php/hhvm/repo.sls

@@ -9,7 +9,7 @@ include:
 
 hhvm_repo:
   pkgrepo.managed:
-    - name: deb http://dl.hhvm.com/{{ salt['grains.get']('os')|lower }} {{ salt['grains.get']('oscodename')}} main
+    - name: deb http://dl.hhvm.com/{{ salt['grains.get']('os')|lower }} {{ salt['grains.get']('oscodename') }} main
     - file: /etc/apt/sources.list.d/hhvm.list
     - keyid: 0x5a16e7281be7a449
     - keyserver: keyserver.ubuntu.com