[PATCH v2] drm/ttm/tests: Fix build failure on PREEMPT_RT

[Maarten Lankhorst <dev@lankhorst.se>]

Fix a compile error in the kunit tests when CONFIG_PREEMPT_RT is
enabled, and the normal mutex is converted into a rtmutex.

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202602261547.3bM6yVAS-lkp@intel.com/
Signed-off-by: Maarten Lankhorst <dev@lankhorst.se>
---
Changes since v1:
- Use the correct locking primitive (Jouni)

 drivers/gpu/drm/ttm/tests/ttm_bo_test.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/ttm/tests/ttm_bo_test.c b/drivers/gpu/drm/ttm/tests/ttm_bo_test.c
index d468f83220720..f3103307b5df9 100644
--- a/drivers/gpu/drm/ttm/tests/ttm_bo_test.c
+++ b/drivers/gpu/drm/ttm/tests/ttm_bo_test.c
@@ -222,13 +222,13 @@ static void ttm_bo_reserve_interrupted(struct kunit *test)
 		KUNIT_FAIL(test, "Couldn't create ttm bo reserve task\n");
 
 	/* Take a lock so the threaded reserve has to wait */
-	mutex_lock(&bo->base.resv->lock.base);
+	dma_resv_lock(bo->base.resv, NULL);
 
 	wake_up_process(task);
 	msleep(20);
 	err = kthread_stop(task);
 
-	mutex_unlock(&bo->base.resv->lock.base);
+	dma_resv_unlock(bo->base.resv);
 
 	KUNIT_ASSERT_EQ(test, err, -ERESTARTSYS);
 }
-- 
2.51.0