tests/hwtable: add test for local configuration dump

tests/hwtable: add test for local configuration dump

This adds another test iteration in test_driver(): It now tests:

 1) with "user-supplied" configuration,
 2) using the full config dump (equivalent with "multipath -t" output),
 3) using the local config dump as implemented in the previous patch.

Again, the properties of paths and maps should be the same for all 3
scenarios. For 3), the "multipath -t" output can't be expected to be
exactly equal to the output in 1), because merging of hwentries may move the
position of a hwentry down in the hwentry list, and empty "multipath"
sections are being added.

Signed-off-by: Martin Wilck <mwilck@suse.com>