pnfs-obj: Rename objlayout_io_state => objlayout_io_res

* All instances of objlayout_io_state => objlayout_io_res
* All instances of state => oir;
* All instances of ol_state => oir;

Big but nothing to it

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>