remove duplicate line

Author: suomesta

reference/memory/shared_ptr/atomic_compare_exchange_strong_explicit.md

@@ -102,7 +102,6 @@ int main()
 ## 参照
 - [`atomic_compare_exchange_strong() - shared_ptr`](atomic_compare_exchange_strong.md)
 - [`atomic_compare_exchange_strong_explicit() - <atomic>`](/reference/atomic/atomic_compare_exchange_strong_explicit.md)
-- [`atomic_compare_exchange_strong_explicit() - <atomic>`](/reference/atomic/atomic_compare_exchange_strong_explicit.md)
 - [N2674 Shared_ptr atomic access, revision 1](http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2674.htm)
 - [C++0x Shared_ptr atomic access - Faith and Brave - C++で遊ぼう](http://faithandbrave.hateblo.jp/entry/20081015/1224066366)
 - [LWG Issue 2172. Does `atomic_compare_exchange_*` accept `v == nullptr` arguments?](http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#2172)

reference/unordered_map/unordered_map/max_load_factor.md

@@ -127,7 +127,6 @@ new load_factor: 1.125
 
 ### 処理系
 - [Clang](/implementation.md#clang): ??
-- [Clang](/implementation.md#clang): ??
 - [GCC](/implementation.md#gcc): ??
 - [ICC](/implementation.md#icc): ?
 - [Visual C++](/implementation.md#visual_cpp): 2012 [mark verified]

reference/unordered_map/unordered_multimap/max_load_factor.md

@@ -129,7 +129,6 @@ new load_factor: 1.125
 
 ### 処理系
 - [Clang](/implementation.md#clang): ??
-- [Clang](/implementation.md#clang): ??
 - [GCC](/implementation.md#gcc): ??
 - [ICC](/implementation.md#icc): ?
 - [Visual C++](/implementation.md#visual_cpp): 2012 [mark verified]