Linux 4.2: total_link_count is no longer accessible

Linux 4.2: total_link_count is no longer accessible

The value is now stored in the nameidata structure which
is private to fs/namei.c, so we can't modify it here.

The effect is that using a path that contains 40+ directories
may fail with ELOOP, depending on which directories in the
path were previously used.  After a directory is accessed once
its D_AUTOMOUNT flag is reset and it will no longer count
against the symlink limit in later path lookups.

Reviewed-on: http://gerrit.openafs.org/11926
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>
(cherry picked from commit 89aeb71a3e23c944f58cfa9572e9eae4d2130d37)

Change-Id: Ib6282f3029c4112c510217eacf270a56d679fccd
Reviewed-on: http://gerrit.openafs.org/11949
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
Reviewed-by: Stephan Wiesand <stephan.wiesand@desy.de>