drm: make drm_mm_init() return void

There is no reason to return "int" as this function never fails.
Furthermore, several drivers (ast, sis) already depend on this.

Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c
index 6e6975c..cb9dd67 100644
--- a/drivers/gpu/drm/ttm/ttm_bo.c
+++ b/drivers/gpu/drm/ttm/ttm_bo.c
@@ -1455,9 +1455,7 @@
 		goto out_no_sys;
 
 	bdev->addr_space_rb = RB_ROOT;
-	ret = drm_mm_init(&bdev->addr_space_mm, file_page_offset, 0x10000000);
-	if (unlikely(ret != 0))
-		goto out_no_addr_mm;
+	drm_mm_init(&bdev->addr_space_mm, file_page_offset, 0x10000000);
 
 	INIT_DELAYED_WORK(&bdev->wq, ttm_bo_delayed_workqueue);
 	INIT_LIST_HEAD(&bdev->ddestroy);
@@ -1471,8 +1469,6 @@
 	mutex_unlock(&glob->device_list_mutex);
 
 	return 0;
-out_no_addr_mm:
-	ttm_bo_clean_mm(bdev, 0);
 out_no_sys:
 	return ret;
 }