drm/ttm/tests: fix incorrect assert in ttm_bo_unreserve_bulk()

drm/ttm/tests: fix incorrect assert in ttm_bo_unreserve_bulk()

In the ttm_bo_unreserve_bulk() test function, resv is allocated using
kunit_kzalloc(), but the subsequent assertion mistakenly verifies the
ttm_dev pointer instead of the resv pointer.

Fix the assertion to properly verify the resv pointer.

Signed-off-by: Qasim Ijaz <qasdev00@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250313161424.10688-1-qasdev00@gmail.com
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Christian König <christian.koenig@amd.com>