Fix reference to 'diff-font-lock-syntax' in diff-mode documentation

* doc/emacs/files.texi (Diff Mode): Add the omitted name of the
variable.  (Bug#47129)

diff --git a/doc/emacs/files.texi b/doc/emacs/files.texi
index 88fcdd0f9f68d1a2e4c7cb1b1e4b97b553d497cd..b9e45b9919f18c75f0e0ffee82aba9d96b3431d0 100644 (file)
--- a/doc/emacs/files.texi
+++ b/doc/emacs/files.texi
@@ -1652,8 +1652,9 @@ modify the original (``old'') source files rather than the patched
 (``new'') source files.
 
 @vindex diff-font-lock-syntax
-  If non-@code{nil}, fragments of source in hunks are highlighted
-according to the appropriate major mode.
+  If @code{diff-font-lock-syntax} is non-@code{nil}, fragments of
+source in hunks are highlighted according to the appropriate major
+mode.
 
 @node Copying and Naming
 @section Copying, Naming and Renaming Files