[depr.atomics.volatile] Use \tcode for template name "atomic" (cplusplus#6213)

Author: AlisdairM

source/future.tex

@@ -2697,7 +2697,7 @@
 \rSec2[depr.atomics.volatile]{Volatile access}
 
 \pnum
-If an atomic specialization has one of the following overloads,
+If an \tcode{atomic}\iref{atomics.types.generic} specialization has one of the following overloads,
 then that overload participates in overload resolution
 even if \tcode{atomic<T>::is_always_lock_free} is \tcode{false}:
 \begin{codeblock}