LU-3868 osc: Update inode timestamp for lockless IO as well

LU-3868 osc: Update inode timestamp for lockless IO as well

Removed the checks for oi_lockless from osc_io_read_start() and
osc_io_write_start(). This patch also removes the unnecessary call to
cl_object_attr_get() in osc_io_write_start() before calling
cl_object_attr_set()

Signed-off-by: Swapnil Pimpale <spimpale@ddn.com>
Change-Id: Ic96694e84444cd19fafe0af72848250e5b1a3d14
Reviewed-on: http://review.whamcloud.com/8797
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: John L. Hammond <john.hammond@intel.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>