LU-4204 tests: fix test_69 in conf-sanity

Recent commit added new test 69 to conf-sanity,
but calls test_68 by mistake. This patch fixes that typo.
In addition the test in its original form could never have worked.
There were several functional problems in it.
This patch fixes these up too.

Test-Parmeters: testlist=conf-sanity envdefinitions=SLOW=yes,ONLY=69

Signed-off-by: Bob Glossman <bob.glossman@intel.com>
Change-Id: I44d1e5f620a3e4cc14b59842abdd2f56ed409872
Reviewed-on: http://review.whamcloud.com/8158
Tested-by: Jenkins
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Nathaniel Clark <nathaniel.l.clark@intel.com>