Remove extra 'std.' prefix from docs for std.clamp

Author: rhowe

doc/ref/stdlib.html

@@ -429,7 +429,7 @@ <h3 id="math">
   <div class="hgroup-inline">
     <div class="panel">
       <h4 id="std.clamp">
-        std.std.clamp(x, minVal, maxVal)
+        std.clamp(x, minVal, maxVal)
       </h4>
     </div>
     <div style="clear: both"></div>