[conv.qual] Fix example for cv-decomposition.

After CWG2051, a cv-decomposition can also be a no-op.

Author: jensmaurer

source/expressions.tex

@@ -717,8 +717,11 @@
 the cv-qualifiers $\cv{}_i$ of the array.
 \begin{example}
 The type denoted by the \grammarterm{type-id} \tcode{const int **}
-has two cv-decompositions,
-taking \tcode{U} as ``\tcode{int}'' and as ``pointer to \tcode{const int}''.
+has three cv-decompositions,
+taking \tcode{U}
+as ``\tcode{int}'',
+as ``pointer to \tcode{const int}'', and
+as ``pointer to pointer to \tcode{const int}''.
 \end{example}
 The $n$-tuple of cv-qualifiers after the first one
 in the longest cv-decomposition of \tcode{T}, that is,