[expr.type] Fix typo

Author: Andreas-Krug

source/expressions.tex

@@ -340,7 +340,7 @@
 the value category of the expression is not altered.
 Let $X$ be the object or function denoted by the reference.
 If a pointer to $X$ would be valid in
-the context of the evalution of the expression\iref{basic.fundamental},
+the context of the evaluation of the expression\iref{basic.fundamental},
 the result designates $X$;
 otherwise, the behavior is undefined.
 \begin{note}