LU-4921 lmv: try all stripes for unknown hash functions

For unknown hash type, LMV should try all stripes to locate
the name entry. But it will only for lookup and unlink, i.e.
we can only list and unlink entries under striped dir with
unknown hash type.

Signed-off-by: wang di <di.wang@intel.com>
Change-Id: Ifeed7131c24e48277a6cc8fd4c09b7534e31079f
Reviewed-on: http://review.whamcloud.com/10041
Tested-by: Jenkins
Reviewed-by: John L. Hammond <john.hammond@intel.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Tested-by: Maloo <hpdd-maloo@intel.com>