EX-4157 lipe: comment out ldiskfs functions for client-only lpcc_purge

EX-4157 lipe: comment out ldiskfs functions for client-only lpcc_purge

Sometime the client system does not have ldiskfs libs, then lpcc_purge
fails to start on it because some ldiskfs symbols cannot be found.
So comment out these codes for a client-only building.

Change-Id: I4a38f1128b9e66d495f94ef7ebd91f26ea052b67
Signed-off-by: Lei Feng <flei@whamcloud.com>
Test-Parameters: trivial testlist=sanity-pcc env=ONLY=200-202,ONLY_REPEAT=50 \
                 clientextra_install_params="--packages lipe-lpcc"
Reviewed-on: https://review.whamcloud.com/45394
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: John L. Hammond <jhammond@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>