LU-7988 hsm: split mdt_hsm_add_actions()

LU-7988 hsm: split mdt_hsm_add_actions()

Split a portion of mdt_hsm_add_actions() to the new function
mdt_hsm_process_hal() in order to re-use it in a subsequent patch.

Lustre-change: https://review.whamcloud.com/20272
Lustre-commit: 3c0b677cdffae7d329e6f0ab73784b20af2f11f5

Signed-off-by: frank zago <fzago@cray.com>
Change-Id: I32785c549a744592d4e84787fd16d12e7ffd7322
Reviewed-by: Quentin Bouget <quentin.bouget@cea.fr>
Reviewed-by: Ben Evans <bevans@cray.com>
Signed-off-by: Minh Diep <minh.diep@intel.com>
Reviewed-on: https://review.whamcloud.com/29583
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: John L. Hammond <john.hammond@intel.com>