drm/radeon/ttm: Fix memory leak userptr pages

If userptr pages have been pinned but not bounded,
they remain uncleared.
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Daniel Gomez <daniel@qtec.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/radeon/radeon_ttm.c

@@ -481,13 +481,14 @@ static void radeon_ttm_backend_unbind(struct ttm_device *bdev, struct ttm_tt *tt
 	struct radeon_ttm_tt *gtt = (void *)ttm;
 	struct radeon_device *rdev = radeon_get_rdev(bdev);
 
+	if (gtt->userptr)
+		radeon_ttm_tt_unpin_userptr(bdev, ttm);
+
 	if (!gtt->bound)
 		return;
 
 	radeon_gart_unbind(rdev, gtt->offset, ttm->num_pages);
 
-	if (gtt->userptr)
-		radeon_ttm_tt_unpin_userptr(bdev, ttm);
 	gtt->bound = false;
 }