LU-9416 hsm: add kkuc before sending registration RPCs

LU-9416 hsm: add kkuc before sending registration RPCs

This avoids a situation where the registration completes and the CDT
sends HSM actions just before the kkuc registration happens. In this
case the client drops the actions because there are no CT pipes in the
kkuc list.

Lustre-change: https://review.whamcloud.com/28751
Lustre-commit: bdb04079570dd2de3b9310221e0206d64efb9ecc

Change-Id: Icbd6575f04c0ca7e8f731ee8481ec72a9ff4f2e1
Signed-off-by: Henri Doreau <henri.doreau@cea.fr>
Reviewed-by: John L. Hammond <john.hammond@intel.com>
Reviewed-by: Faccini Bruno <bruno.faccini@intel.com>
Signed-off-by: Minh Diep <minh.diep@intel.com>
Reviewed-on: https://review.whamcloud.com/29687
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>