LU-8130 ldlm: store name directly in namespace.

LU-8130 ldlm: store name directly in namespace.

Rather than storing the name of a namespace in the
hash table, store it directly in the namespace.
This will allow the hashtable to be changed to use
rhashtable.

Linux-commit: 648ae363628c84faa8d8861e3246e096b8c0a392

Change-Id: Ie5bb8092c9e1831fbc38beade46be6d35f3256dc
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: James Simmons <uja.ornl@yahoo.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-on: https://review.whamcloud.com/32408
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by: Dmitry Eremin <dmitry.eremin@intel.com>
Reviewed-by: Mike Pershin <mike.pershin@intel.com>
Reviewed-by: John L. Hammond <john.hammond@intel.com>