kernel test robot and Stephen Rothwell reported htmldocs warning:

Documentation/admin-guide/cgroup-v1/memory.rst:723: WARNING: Title underline too short.

Extend underline in section 8 heading to match the text in order to fix
the warning.

Link: https://lore.kernel.org/linux-doc/202212180030.OzPG7QHL-lkp@intel.com/
Link: https://lore.kernel.org/linux-next/20221218062235.443758ae@canb.auug.org.au/
Fixes: f8bc956f6ea695 ("mm: memcontrol: deprecate charge moving")
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com>
---
 Documentation/admin-guide/cgroup-v1/memory.rst | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Documentation/admin-guide/cgroup-v1/memory.rst b/Documentation/admin-guide/cgroup-v1/memory.rst
index 87d7877b98ec79..258e45cc3b2db1 100644
--- a/Documentation/admin-guide/cgroup-v1/memory.rst
+++ b/Documentation/admin-guide/cgroup-v1/memory.rst
@@ -720,7 +720,7 @@ NOTE2:
        otherwise the hard limit will take precedence.
 
 8. Move charges at task migration (DEPRECATED!)
-=================================
+===============================================
 
 THIS IS DEPRECATED!
 
-- 
An old man doll... just what I always wanted! - Clara