LU-1657 lov: LBUG at lov_fini_raid0()

LU-1657 lov: LBUG at lov_fini_raid0()

The refcount of lsm could be greater than 1 if the object was failed
at initialization because llite held another reference.

Signed-off-by: Jinshan Xiong <jinshan.xiong@intel.com>
Change-Id: I86884eb36f256123e835fdc9e0e585a984f7713a
Reviewed-on: http://review.whamcloud.com/3513
Reviewed-by: Johann Lombardi <johann@whamcloud.com>
Reviewed-by: jacques-Charles Lafoucriere <jacques-charles.lafoucriere@cea.fr>
Tested-by: Hudson
Tested-by: Maloo <whamcloud.maloo@gmail.com>