test/setup: Use hw_sector_size to convert size to sectors

The {logical,physical}_block_size may actually differ (physical can
be bigger than logical) so always use the smallest available unit -
the hw_sector_size is an actual alias to logical_block_size and it's
also clearly indicating what unit sgdisk is working with.

In case the physical_block_size differs, the resulted partitions may
have different size than expected. For instance, under nvme with
512/4096 layout, the partitions were ending up 128MB in size instead
of 1GB causing the dmsetup to fail (as it expects to join partitions
1GB in size each).

cherry-pick: 26c2f987
Signed-off-by: Michal Berger <michal.berger@intel.com>
Change-Id: Ib6d3afd3471af2c2e9a5ced17004dd9c565708c8
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/17094


Reviewed-by: Pawel Piatek <pawelx.piatek@intel.com>
Reviewed-by: Kamil Godzwon <kamilx.godzwon@intel.com>
Reviewed-by: Konrad Sztyber <konrad.sztyber@intel.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>
Reviewed-by: Tomasz Zawadzki <tomasz.zawadzki@intel.com>
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>