Fixing whitespace problems

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@111750 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/__mutex_base b/include/__mutex_base
index 57088be..bcfce16 100644
--- a/include/__mutex_base
+++ b/include/__mutex_base
@@ -129,7 +129,7 @@
             __u.__owns_ = false;
             return *this;
         }
-#endif
+#endif  // _LIBCPP_MOVE
 
     void lock();
     bool try_lock();