Fix $(location) syntax in documentation.

RELNOTES: None.
PiperOrigin-RevId: 293938752
diff --git a/src/main/java/com/google/devtools/build/docgen/templates/be/make-variables.vm b/src/main/java/com/google/devtools/build/docgen/templates/be/make-variables.vm
index c0794bd..0999ac4 100644
--- a/src/main/java/com/google/devtools/build/docgen/templates/be/make-variables.vm
+++ b/src/main/java/com/google/devtools/build/docgen/templates/be/make-variables.vm
@@ -123,7 +123,7 @@
 
     <p>
       If you want to run a tool from within a <code>genrule</code>, the
-      recommended way to get its path is <code>($<a
+      recommended way to get its path is <code>$(<a
       href="#predefined_label_variables">execpath</a> toolname)</code>,
       where <i>toolname</i> must be listed in the <code>genrule</code>'s
       <code><a