DAFS: VRS_r with VOL_SALVAGE_NO_OFFLINE in attach2

DAFS: VRS_r with VOL_SALVAGE_NO_OFFLINE in attach2

One caller of VRequestSalvage_r in attach2 was not passing the
VOL_SALVAGE_NO_OFFLINE flag. This really should be passed for every
place that manually sets vp->nUsers = 0, since then the VPutVolume_r
handlers will never fire.

Change-Id: I088d93a6c598a4d636224f4cf4c0d89454efcca8
Reviewed-on: http://gerrit.openafs.org/8203
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Derrick Brashear <shadow@your-file-system.com>