vol: fix OS_LOCKFILE/OS_UNLOCKFILE for Windows

vol: fix OS_LOCKFILE/OS_UNLOCKFILE for Windows

On UNIX the OS_LOCKFILE and OS_UNLOCKFILE macros return zero
on success.  Since Windows LockFile() and UnlockFile() return
non-zero (TRUE) on success, negate the return value as part
of the macro definition.

(cherry picked from commit e8e69d5b2c611df249fd613ed068fc030a0e30d1)
Reviewed-on: http://gerrit.openafs.org/3664
Reviewed-by: Derrick Brashear <shadow@dementia.org>
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Change-Id: Ifc9f7efcafee5a17fcf112556184be0072deb108
Reviewed-on: http://gerrit.openafs.org/3823
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Derrick Brashear <shadow@dementia.org>