Do not rely on vol header for V*VolumeHandles_r

Do not rely on vol header for V*VolumeHandles_r

VCloseVolumeHandles_r and VReleaseVolumeHandles_r were using V_id to get
the id of the volume; just use vp->hashid so we can call these even if
we lack a header.

Change-Id: I0f0bc0ae82a7b86135aebe194c79a223a6f25094
Reviewed-on: http://gerrit.openafs.org/1348
Tested-by: Andrew Deason <adeason@sinenomine.net>
Reviewed-by: Alistair Ferguson <alistair.ferguson@mac.com>
Reviewed-by: Derrick Brashear <shadow@dementia.org>
Tested-by: Derrick Brashear <shadow@dementia.org>