staging: lustre: lov: add cl_object_layout_get()

Add cl_object_layout_get() to return the layout and generation of an
object. Replace some direct accesses to object LSM with calls to this
function.

In ll_getxattr() factor out the LOV xattr specific handling into a new
function ll_getxattr_lov() which calls cl_object_layout_get(). In
ll_listxattr() call ll_getxattr_lov() to determine if a lustre.lov
xattr should be emitted.  Add lov_lsm_pack() to generate LOV xattrs
from a LSM.

Remove the unused functions ccc_inode_lsm_{get,put}() and
lov_lsm_get().

Signed-off-by: John L. Hammond <john.hammond@intel.com>
Signed-off-by: Jinshan Xiong <jinshan.xiong@intel.com>
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-5814
Reviewed-on: http://review.whamcloud.com/13680


Reviewed-by: Bobi Jam <bobijam@hotmail.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>
Signed-off-by: James Simmons <jsimmons@infradead.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>