Eliminate superfluous exclusive_scan declaration in synopsis

Author: jaredhoberock

algorithms.html

@@ -513,10 +513,12 @@ <h1>Header <code>&lt;experimental/numeric&gt;</code><ins2> synopsis</ins2></h1>
     T reduce(InputIterator first, InputIterator last, T init,
              BinaryOperation binary_op);
 
+  <del2>
   template&lt;class InputIterator, class OutputIterator&gt;
     OutputIterator
       exclusive_scan(InputIterator first, InputIterator last,
                      OutputIterator result);
+  </del2>
   template&lt;class InputIterator, class OutputIterator,
            class T&gt;
     OutputIterator