Convert ObtainSalvageLock to the VLockFile API
Make ObtainSalvageLock use the VLockFile API, to consolidate
platform-specific locking code, and to make it possible to acquire a
shared lock on the salvage lock file. Create the ObtainSharedSalvageLock
function to acquire such a lock.
Change-Id: Ieadd77ac8d4030b31c48fff1c98712a6c95f93ad
Reviewed-on: http://gerrit.openafs.org/1347
Tested-by: Andrew Deason <adeason@sinenomine.net>
Reviewed-by: Derrick Brashear <shadow@dementia.org>
Tested-by: Derrick Brashear <shadow@dementia.org>