LINUX: More flock fixes

LINUX: More flock fixes

Turns out the we have two almost identical lock routines on Linux,
one for POSIX locks, and one for flocks. Fix them both. Also,
while we're at it, make the same fixes in the LINUX24 tree.

Thanks to Andrew Deason for pointing out the oversight in the
original patch (5abe706a7e237d3872db3638d947a14c935370d5)

Change-Id: I59f0f1e12af36a97e490df36537ac17e8ed87303
Reviewed-on: http://gerrit.openafs.org/2535
Reviewed-by: Andrew Deason <adeason@sinenomine.net>
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@openafs.org>