lustre/clio: honor O_NOATIME

lustre/clio: honor O_NOATIME

Add a ci_noatime bit to struct cl_io. In ll_io_init() set this bit if
O_NOATIME is set in f_flags. Ensure that this bit is propagated down
to lower layers. In osc_io_read_start() don't update atime if this bit
is set. Add sanity test 39n to check that passing O_NOATIME to open()
is honored.

Signed-off-by: John L. Hammond <john.hammond@intel.com>
Reviewed-on: http://review.whamcloud.com/7442
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-3832
Reviewed-by: Jinshan Xiong <jinshan.xiong@intel.com>
Reviewed-by: Lai Siyao <lai.siyao@intel.com>
Tested-by: Maloo <whamcloud.maloo@gmail.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>
Signed-off-by: Oleg Drokin <oleg.drokin@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>