LU-6221 utils: hsm_root is also required for --dry-run

LU-6221 utils: hsm_root is also required for --dry-run

Not specifying hsm_root in copytool/lhsmtool_posix command line for
--dry-run mode can lead to failure/error.
This path ensures that hsm_root will be required even for --dry-run.

Signed-off-by: Bruno Faccini <bruno.faccini@intel.com>
Change-Id: Icaa2af6d1365751d9e77b2be3f60aacc9c1f6a5c
Reviewed-on: http://review.whamcloud.com/13673
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Henri Doreau <henri.doreau@cea.fr>
Reviewed-by: Hongchao Zhang <hongchao.zhang@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>