drm: minor kref_put() nits

There's no need to pass kref_put() the address of a function (just the
function will do just fine) nor to cast its unused return to void.

Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
diff --git a/drivers/gpu/drm/radeon/radeon_fence.c b/drivers/gpu/drm/radeon/radeon_fence.c
index 9e59868..ab83472 100644
--- a/drivers/gpu/drm/radeon/radeon_fence.c
+++ b/drivers/gpu/drm/radeon/radeon_fence.c
@@ -322,7 +322,7 @@
 
 	*fence = NULL;
 	if (tmp) {
-		kref_put(&tmp->kref, &radeon_fence_destroy);
+		kref_put(&tmp->kref, radeon_fence_destroy);
 	}
 }
 
diff --git a/drivers/gpu/drm/ttm/ttm_object.c b/drivers/gpu/drm/ttm/ttm_object.c
index 75e9d6f..ebddd44 100644
--- a/drivers/gpu/drm/ttm/ttm_object.c
+++ b/drivers/gpu/drm/ttm/ttm_object.c
@@ -206,7 +206,7 @@
 	 */
 
 	write_lock(&tdev->object_lock);
-	(void)kref_put(&base->refcount, &ttm_release_base);
+	kref_put(&base->refcount, ttm_release_base);
 	write_unlock(&tdev->object_lock);
 }
 EXPORT_SYMBOL(ttm_base_object_unref);