[format.range.fmtmap] Fix undefined type name

Author: hewillk

source/utilities.tex

@@ -16736,7 +16736,7 @@
 \exposid{element-type} is a specialization of \tcode{pair}, or
 \item
 \exposid{element-type} is a specialization of \tcode{tuple} and
-\tcode{tuple_size_v<T> == 2}.
+\tcode{tuple_size_v<\exposid{element-type}> == 2}.
 \end{itemize}
 
 \pnum