fixup: markup

Author: jensmaurer

source/declarations.tex

@@ -5575,7 +5575,7 @@
 If the initializer list is
 a brace-enclosed \grammarterm{designated-initializer-list},
 the aggregate shall be of class type \tcode{C}.
-For each \tcode{designator}
+For each \grammarterm{designator}
 within the \grammarterm{designated-only-initializer-list}
 of the \grammarterm{designated-initializer-list},
 the lookup set for the \grammarterm{identifier}