LU-1187 osd: add agent/local inode for remote directory

A local inode will be created for remote directory entry, so
to make e2fsck check pass.

The remote directory on the remote MDT will be put under the
agent directory.

Remove LA_TYPE checking during osd_inode_set, because when
initialize the remote object, it needs to get TYPE information
from remote attr get, where we need type information anyway,
(osp_md_attr_get ->out_attr_get->osd_attr_get | LA_TYPE).
So osd_attr_get will always return LA_TYPE valid information
here, then if it do attr_get/modify/attr_set might hit this
ASSERT, So during osd_attr_set, we can just ignore type.

Signed-off-by: wang di <di.wang@intel.com>
Change-Id: I7f177fa8ae2ab450cde78a8c2da9a2770ec6b0cb
Reviewed-on: http://review.whamcloud.com/4931
Reviewed-by: Alex Zhuravlev <alexey.zhuravlev@intel.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Tested-by: Hudson
Tested-by: Maloo <whamcloud.maloo@gmail.com>