ocfs2: send correct UUID to cleancache initialization

ocfs2: Fix cleancache initialization call to correctly pass uuid

As reported by Steven Whitehouse in https://lkml.org/lkml/2011/5/27/221
the ocfs2 volume UUID is incorrectly passed to cleancache.
As a result, shared-ephemeral tmem pools will not actually
be created; instead they will be private (unshared) which
misses out on a major benefit of tmem.

Reported-by: Steven Whitehouse <swhiteho@redhat.com>
Signed-off-by: Dan Magenheimer <dan.magenheimer@oracle.com>
Signed-off-by: Joel Becker <jlbec@evilplan.org>