LU-4340 tests: Correct conf-sanity test 69

LU-4340 tests: Correct conf-sanity test 69

conf-sanity test 69 can fail due to creating more files than
available inodes on the first OST. We need to create the same number
of files, but in small numbers and remove them after creation.
Removing the newly created files will help in small OST environments
like the conf-sanity environment. If the LAST_ID is already greater
than 5 * OST_MAX_PRECREATE, just perform the OST replacement.

Test-Parameters: envdefinitions=SLOW=yes testlist=conf-sanity

Signed-off-by: James Nunez <james.a.nunez@intel.com>
Change-Id: I565b7d81c1817e4ee14f85314990b85ba8c844f1
Reviewed-on: http://review.whamcloud.com/15966
Tested-by: Jenkins
Reviewed-by: Ashish Purkar <ashish.purkar@seagate.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by: Jian Yu <jian.yu@intel.com>