LU-3831 llite: Remove touch_atime() call in ll_readdir()

LU-3831 llite: Remove touch_atime() call in ll_readdir()

In 2.6.32 vfs_readdir() calls file_accessed() which checks for
O_NOATIME and calls touch_atime() appropriately. In 3.11, the same is
true of iterate_dir(). Hence removed the call to touch_atime() in
ll_readdir(). Also, removed the HAVE_TOUCH_ATIME_1ARG and
HAVE_F_PATH_MNT autocrud since ll_readdir() was the last caller of
touch_atime() in the lustre tree.

Signed-off-by: Swapnil Pimpale <spimpale@ddn.com>
Change-Id: Iedd3be29adae80427d71a7eb5a0f8c0d1f1d2924
Reviewed-on: http://review.whamcloud.com/8664
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Lai Siyao <lai.siyao@intel.com>
Reviewed-by: Yang Sheng <yang.sheng@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>