LU-12214 build: fix build without lustre_utils

LU-12214 build: fix build without lustre_utils

fix build without_lustre_utils enabled.
library and tools man pages separated to avoid package
build breakage.

Cray-bug-id: LUS-6036
Test-parameters: trivial
Change-Id: I0dbf821cff85b336d26555b6f2a8b659d9203de9
Signed-off-by: Alexey Lyashkov <c17817@cray.com>
Reviewed-on: https://review.whamcloud.com/36429
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Alexander Boyko <alexander.boyko@hpe.com>
Reviewed-by: Olaf Faaland-LLNL <faaland1@llnl.gov>
Reviewed-by: Oleg Drokin <green@whamcloud.com>