[gcc r12-9490] libstdc++: Fix error in doxygen comments in <atomic>

[Jonathan Wakely]

https://gcc.gnu.org/g:26891127b03bc44ac7672205adaaba635392cdb1

commit r12-9490-g26891127b03bc44ac7672205adaaba635392cdb1
Author: Jonathan Wakely <jwakely@redhat.com>
Date:   Thu Apr 27 21:50:30 2023 +0100

    libstdc++: Fix error in doxygen comments in <atomic>
    
    libstdc++-v3/ChangeLog:
    
            * include/std/atomic: Add missing @endcond doxygen comment.

Diff:
---
 libstdc++-v3/include/std/atomic | 1 +
 1 file changed, 1 insertion(+)

diff --git a/libstdc++-v3/include/std/atomic b/libstdc++-v3/include/std/atomic
index faf7eb95594..94150c1181f 100644
--- a/libstdc++-v3/include/std/atomic
+++ b/libstdc++-v3/include/std/atomic
@@ -1287,6 +1287,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     using __atomic_val_t = __type_identity_t<_Tp>;
   template<typename _Tp>
     using __atomic_diff_t = typename atomic<_Tp>::difference_type;
+  /// @endcond
 
   // [atomics.nonmembers] Non-member functions.
   // Function templates generally applicable to atomic types.