[PATCH] doc/zh_CN: resolve undefined label warning in admin-guide index

[Lukas Bulwahn]

Documentation generation warns:

  Documentation/translations/zh_CN/admin-guide/index.rst:3:
  WARNING: undefined label: documentation/admin-guide/index.rst

Use doc reference for .rst files to resolve the warning.

Fixes: 37a607cf2318 ("doc/zh_CN: add admin-guide index")
Signed-off-by: Lukas Bulwahn <lukas.bulwahn@xxxxxxxxx>
---
Alex, please ack.

Jonathan, please pick this quick minor warning fix.

applies on your docs-next and next-20200731

 Documentation/translations/zh_CN/admin-guide/index.rst | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Documentation/translations/zh_CN/admin-guide/index.rst b/Documentation/translations/zh_CN/admin-guide/index.rst
index 7d502fa5da64..ed5ab7e37f38 100644
--- a/Documentation/translations/zh_CN/admin-guide/index.rst
+++ b/Documentation/translations/zh_CN/admin-guide/index.rst
@@ -1,6 +1,6 @@
 .. include:: ../disclaimer-zh_CN.rst
 
-:Original: :ref:`Documentation/admin-guide/index.rst`
+:Original: :doc:`../../../admin-guide/index`
 :Translator: Alex Shi <alex.shi@xxxxxxxxxxxxxxxxx>
 
 
-- 
2.17.1