LU-6215 llite: handle kernel symlink api changes in 4.2+

LU-6215 llite: handle kernel symlink api changes in 4.2+
 kernels

Starting with 4.2 kernels the inode operations handling
symlinks follow_link() and put_link() stop passing in
struct nameidata as an argument. This patch handles this
change.

Change-Id: I204daa1469f6661ced3a519873e1aa26463c8c72
Signed-off-by: James Simmons <uja.ornl@yahoo.com>
Reviewed-on: http://review.whamcloud.com/16376
Tested-by: Jenkins
Reviewed-by: frank zago <fzago@cray.com>
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Dmitry Eremin <dmitry.eremin@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>