LU-2556 osp: count requests in osp_sync_interpret() only

LU-2556 osp: count requests in osp_sync_interpret() only

as it's called by ptlrpc always, so any counting in
osp_sync_request_commit_cb() is extra and wrong.

Signed-off-by: Alex Zhuravlev <alexey.zhuravlev@intel.com>
Change-Id: Ib67ba11d2c382b1ff9cd19522ce9e15b57ebca94
Reviewed-on: http://review.whamcloud.com/5453
Tested-by: Hudson
Tested-by: Maloo <whamcloud.maloo@gmail.com>
Reviewed-by: wangdi <di.wang@intel.com>
Reviewed-by: Fan Yong <fan.yong@intel.com>
Tested-by: Oleg Drokin <oleg.drokin@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>