[PATCH] docs: cxl/core: Fix the title underline

Commit 5f653f7590ab ("cxl/core: Rename bus.c to core.c") has changed
the title, but missed to update the underline length, which causes
the following 'make htmldocs' build warning:

Documentation/driver-api/cxl/memory-devices.rst:32: WARNING: Title underline too short.

Fix the title underline accordingly.

Fixes: 5f653f7590ab ("cxl/core: Rename bus.c to core.c") 
Signed-off-by: Fabio Estevam <festevam@gmail.com>
---
 Documentation/driver-api/cxl/memory-devices.rst | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Documentation/driver-api/cxl/memory-devices.rst b/Documentation/driver-api/cxl/memory-devices.rst
index 71495ed77069..73f6b246c583 100644
--- a/Documentation/driver-api/cxl/memory-devices.rst
+++ b/Documentation/driver-api/cxl/memory-devices.rst

@@ -29,7 +29,7 @@ CXL Memory Device
    :internal:
 
 CXL Core
--------
+--------
 .. kernel-doc:: drivers/cxl/core.c
    :doc: cxl core
 

-- 
2.25.1