doc: ReSTify Smack.txt

Adjusts for ReST markup and moves under LSM admin guide.

Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
diff --git a/MAINTAINERS b/MAINTAINERS
index 38a3d95..ce6744e 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -11876,7 +11876,7 @@
 W:	http://schaufler-ca.com
 T:	git git://github.com/cschaufler/smack-next
 S:	Maintained
-F:	Documentation/security/Smack.txt
+F:	Documentation/admin-guide/LSM/Smack.rst
 F:	security/smack/
 
 DRIVERS FOR ADAPTIVE VOLTAGE SCALING (AVS)