docs: Update some out of date sourcetree information

Reviewed-by: Andreas Boll <andreas.boll.dev@gmail.com>
Signed-off-by: Andreas Boll <andreas.boll.dev@gmail.com>
diff --git a/docs/devinfo.html b/docs/devinfo.html
index bf77259..4c1099c 100644
--- a/docs/devinfo.html
+++ b/docs/devinfo.html
@@ -36,7 +36,7 @@
    </pre>
 </li>
 <li>
-   In the src/mesa/glapi/ directory, add the new extension functions and
+   In the src/mapi/glapi/gen/ directory, add the new extension functions and
    enums to the gl_API.xml file.
    Then, a bunch of source files must be regenerated by executing the
    corresponding Python scripts.