Update synopsis for list/forward_list/deque to match the allocator style of existing comment. No code change

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@190320 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/deque b/include/deque
index 5bb8ff7..e552858 100644
--- a/include/deque
+++ b/include/deque
@@ -41,7 +41,7 @@
     deque() noexcept(is_nothrow_default_constructible<allocator_type>::value);
     explicit deque(const allocator_type& a);
     explicit deque(size_type n);
-    explicit deque(size_type n, const Allocator& a); // C++14
+    explicit deque(size_type n, const allocator_type& a); // C++14
     deque(size_type n, const value_type& v);
     deque(size_type n, const value_type& v, const allocator_type& a);
     template <class InputIterator>