LU-8050 osp: not use obdo::o_lcookie for non-onwire RPC data

LU-8050 osp: not use obdo::o_lcookie for non-onwire RPC data

Originally, obdo::o_lcookie is for destroy with unlink cookie from
MDS, it is obsolete in 2.8. And then, it is reused by the OSP to
avoid RAM allocations. But now, we needs more fields in the obdo
structure to transfer more information from client to OST. The
obdo::o_lcookie is good candidate. So this patch adjust OSP
logic to NOT use such field for non-onwire RPC data usage.

Signed-off-by: Fan Yong <fan.yong@intel.com>
Change-Id: I2bff0dce6f00f330657097a9ae9f775396e090cb
Reviewed-on: https://review.whamcloud.com/24876
Reviewed-by: Niu Yawei <yawei.niu@intel.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>