Correct the URL to the attrib.incl file.

llvm-svn: 30276
diff --git a/llvm/docs/doxygen.footer b/llvm/docs/doxygen.footer
index 444e6a3..4ef19e5 100644
--- a/llvm/docs/doxygen.footer
+++ b/llvm/docs/doxygen.footer
@@ -7,7 +7,7 @@
 All Rights Reserved.</p>
 
 <hr>
-<!--#include virtual="attrib.incl" -->
+<!--#include virtual="/attrib.incl" -->
 
 </body>
 </html>