LU-8221 osc: fix for lu_ref feature in osc_extent_put()

LU-8221 osc: fix for lu_ref feature in osc_extent_put()

Trying to enable and use the USE_LU_REF/lu_ref feature, a previous
clio related changes have been found to silently (as feature
has not been tested since!) break it.

In osc_extent_put(), there is no need to remove an
implicit "handle" reference, by using LDLM_LOCK_PUT() macro, since
it has never been acquired before. This was introduced by
3f3a24d LU-3259 clio: cl_lock simplification

And the "osc_extent" reference must be deleted instead added.

This patch makes the necessary changes to fix all of these.

Signed-off-by: Bruno Faccini <bruno.faccini@intel.com>
Change-Id: I86599ff97310b16c9599b6a52a88693872ae6d30
Reviewed-on: https://review.whamcloud.com/20519
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Shaun Tancheff <shaun.tancheff@hpe.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>