LU-4223 tests: fix conf-sanity test_32 typo

LU-4223 tests: fix conf-sanity test_32 typo

The t32_wait_til_devices_gone() function incorrectly calls
"lctl devices_list" instead of "lctl device_list" if there
is a timeout waiting for the loop devices to be cleaned up.
Since this is only used for debugging output after an error,
it wasn't actually causing any additional failures.

Signed-off-by: Andreas Dilger <andreas.dilger@intel.com>
Change-Id: I858e789b16251835bce7af46e4f5233c95500c1e
Reviewed-on: http://review.whamcloud.com/13265
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Jian Yu <jian.yu@intel.com>
Reviewed-by: James Nunez <james.a.nunez@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>