LU-4423 llite: remove ll_readlink as unnecessary

LU-4423 llite: remove ll_readlink as unnecessary

Taken from kernel upstrem by Al Viro:
lustre: generic_readlink() is just fine there, TYVM...

Linux-commit: 4efcc9ffcd4fc53f1f7de539842cdffa1f8e5ecc

Change-Id: I3693f5b7871f9a013c98f962eb9299ffbe32b705
Signed-off-by: Oleg Drokin <oleg.drokin@intel.com>
Signed-off-by: James Simmons <uja.ornl@gmail.com>
Reviewed-on: http://review.whamcloud.com/10123
Tested-by: Jenkins
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Bob Glossman <bob.glossman@intel.com>