LU-9312 hsm: release restore lock without object

LU-9312 hsm: release restore lock without object

In the error path of mdt_hsm_agent_send(), the object to be restored
is not needed to release the layout lock so don't find it.

Signed-off-by: John L. Hammond <john.hammond@intel.com>
Change-Id: Ic8e82a5ccd8f83cac2d7ebc3d4b800f8a4563ca6
Reviewed-on: https://review.whamcloud.com/26742
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Faccini Bruno <bruno.faccini@intel.com>
Reviewed-by: Henri Doreau <henri.doreau@cea.fr>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>