LU-5058 llite: support root squash on newer kernels

LU-5058 llite: support root squash on newer kernels

The fix for the root squash bug for LU-1778 does not
handle the new namespace changes in newer kernels.
This patch restores that functionality.

Change-Id: I2b3bd8a18b94108cc78f55e33f61fa788e353721
Signed-off-by: James Simmons <uja.ornl@gmail.com>
Reviewed-on: http://review.whamcloud.com/10325
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Bob Glossman <bob.glossman@intel.com>
Reviewed-by: Grégoire Pichon <gregoire.pichon@bull.net>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>