restapi : Missing permissions link ast /vmpools url

There is missing <link href="/api/vmpools/{id}/permissions" rel="permissions"/>
element for vmpools, only at /vmpools url.
It is ok for /vmpools/{vmpool:id}.

Change-Id: Id9ce7e04680cf7182e89406e76bcf8d770e3ccfb
Bug-Url: https://bugzilla.redhat.com/977304
Signed-off-by: Ravi Nori <rnori@redhat.com>