[PATCH] VDUSE: fix documentation underline warning

[Randy Dunlap]

Fix a VDUSE documentation build warning:

Documentation/userspace-api/vduse.rst:21: WARNING: Title underline too short.

Fixes: 7bc7f61897b6 ("Documentation: Add documentation for VDUSE")
Signed-off-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
Cc: Xie Yongji <xieyongji@xxxxxxxxxxxxx>
Cc: Jason Wang <jasowang@xxxxxxxxxx>
Cc: Michael S. Tsirkin <mst@xxxxxxxxxx>
Cc: virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx
Cc: Jonathan Corbet <corbet@xxxxxxx>
Cc: linux-doc@xxxxxxxxxxxxxxx
---
 Documentation/userspace-api/vduse.rst |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- lnx-515-rc4.orig/Documentation/userspace-api/vduse.rst
+++ lnx-515-rc4/Documentation/userspace-api/vduse.rst
@@ -18,7 +18,7 @@ types can be added after the security is
 is clarified or fixed in the future.
 
 Create/Destroy VDUSE devices
-------------------------
+----------------------------
 
 VDUSE devices are created as follows: