[algorithm.syn,alg.fill] Fix typos in constraints (#6957)

Author: hewillk

source/algorithms.tex

@@ -1672,7 +1672,7 @@
       requires @\libconcept{output_range}@<R, const T&>
       constexpr borrowed_iterator_t<R> fill(R&& r, const T& value);
     template<class O, class T = iter_value_t<O>>
-      requires @\libconcept{output_iterator}@<O, const T&> O>
+      requires @\libconcept{output_iterator}@<O, const T&>
       constexpr O fill_n(O first, iter_difference_t<O> n, const T& value);
   }
 
@@ -5692,10 +5692,10 @@
   requires @\libconcept{output_iterator}@<O, const T&>
   constexpr O ranges::fill(O first, S last, const T& value);
 template<class R, class T = range_value_t<R>>
-  requires @\libconcept{output_range}@<R, const T&>>
+  requires @\libconcept{output_range}@<R, const T&>
   constexpr borrowed_iterator_t<R> ranges::fill(R&& r, const T& value);
 template<class O, class T = iter_value_t<O>>
-  requires @\libconcept{output_iterator}@<O, const T&>>
+  requires @\libconcept{output_iterator}@<O, const T&>
   constexpr O ranges::fill_n(O first, iter_difference_t<O> n, const T& value);
 \end{itemdecl}