LU-3709 mdt: CDT cleanup follow-on patch

LU-3709 mdt: CDT cleanup follow-on patch

This patch implements the comments made during the review after
maloo passed test or after the landing.

rename in hai_zero() hai_first()
 Use a better name for hai helper

replace use of cfs_helpers by native one in CDT
 replace cfs_atomic_t and helpers
 replace cfs_list and helpers
 change list_for_each + list_entry by list_entry_for_each
 replace cfs_task_t

clean err msg in HSM agent interface
 remove duplicate rc print

parenthesis code cleaning
 remove useless () in conditionnal tests

Signed-off-by: JC Lafoucriere <jacques-charles.lafoucriere@cea.fr>
Change-Id: Ib57f5b4ed7023c18d71bdb620ed53f9b9fa41a3e
Reviewed-on: http://review.whamcloud.com/7254
Tested-by: Hudson
Reviewed-by: Jinshan Xiong <jinshan.xiong@intel.com>
Reviewed-by: John L. Hammond <john.hammond@intel.com>
Tested-by: Maloo <whamcloud.maloo@gmail.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>