LU-5006 mdd: don't call attr_set on object create

LU-5006 mdd: don't call attr_set on object create

The object attr has been initialzed in OSD layer when create
object, it's not necessary to initialize it again in MDD layer.

Signed-off-by: Niu Yawei <yawei.niu@intel.com>
Change-Id: I6f4094d4384b2c153d4dad2666d64281c0450059
Reviewed-on: http://review.whamcloud.com/12243
Tested-by: Jenkins
Reviewed-by: Alex Zhuravlev <alexey.zhuravlev@intel.com>
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Bobi Jam <bobijam@gmail.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>