drm/ttm/tests: Fix argument in ttm_tt_kunit_init()

Remove a leftover definition of page order and pass an empty flag value
in ttm_pool_pre_populated().

Signed-off-by: Karolina Stolarek <karolina.stolarek@intel.com>
Tested-by: Amaranath Somalapuram <Amaranath.Somalapuram@amd.com>
Reviewed-by: Dominik Karol Piątkowski <dominik.karol.piatkowski@intel.com>
Acked-by: Christian König <christian.koenig@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/db34f34a039cf951c5933e8ae046b4ed72d20dcb.1704959786.git.karolina.stolarek@intel.com


Signed-off-by: Christian König <christian.koenig@amd.com>