docs: update piglit url

Signed-off-by: Brian Paul <brianp@vmware.com>
diff --git a/docs/shading.html b/docs/shading.html
index a9b7cfc..17cf35c 100644
--- a/docs/shading.html
+++ b/docs/shading.html
@@ -243,7 +243,7 @@
 </p>
 
 <p>
-The <a href="http://people.freedesktop.org/~nh/piglit/" target="_parent">Piglit</a> project
+The <a href="http://piglit.freedesktop.org/" target="_parent">Piglit</a> project
 has many GLSL tests and the
 <a href="http://glean.sf.net" target="_parent">Glean</a> glsl1 test 
 tests GLSL features.