[PATCH 1/2] dma-fence: Silence sparse warning in dma_fence_describe

[Tvrtko Ursulin <tvrtko.ursulin@igalia.com>]

Sparse complains about assigning a string to a __rcu annotated local
variable:

drivers/dma-buf/dma-fence.c:1040:38: warning: incorrect type in initializer (different address spaces)
drivers/dma-buf/dma-fence.c:1040:38:    expected char const [noderef] __rcu *timeline
drivers/dma-buf/dma-fence.c:1040:38:    got char *
drivers/dma-buf/dma-fence.c:1041:36: warning: incorrect type in initializer (different address spaces)
drivers/dma-buf/dma-fence.c:1041:36:    expected char const [noderef] __rcu *driver
drivers/dma-buf/dma-fence.c:1041:36:    got char *

It is harmless but lets silence it.

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@igalia.com>
Fixes: ac364014fd81 ("dma-buf: cleanup dma_fence_describe v3")
Cc: Christian König <christian.koenig@amd.com>
Cc: linux-media@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Cc: linaro-mm-sig@lists.linaro.org
Reviewed-by: Christian König <christian.koenig@amd.com>
---
 drivers/dma-buf/dma-fence.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/dma-buf/dma-fence.c b/drivers/dma-buf/dma-fence.c
index 1826ba73094c..a2aa82f4eedd 100644
--- a/drivers/dma-buf/dma-fence.c
+++ b/drivers/dma-buf/dma-fence.c
@@ -1037,8 +1037,8 @@ EXPORT_SYMBOL(dma_fence_set_deadline);
  */
 void dma_fence_describe(struct dma_fence *fence, struct seq_file *seq)
 {
-	const char __rcu *timeline = "";
-	const char __rcu *driver = "";
+	const char __rcu *timeline = (const char __rcu *)"";
+	const char __rcu *driver = (const char __rcu *)"";
 	const char *signaled = "";
 
 	rcu_read_lock();
-- 
2.52.0