[task.state] Fix misplaced \end{itemize}

Author: tkoeppe

source/exec.tex

@@ -7343,12 +7343,12 @@
 \item \exposid{own-env}
 with \tcode{\exposid{own-env-t}(get_env(\exposid{rcvr}))} if that expression
 is valid and \tcode{\exposid{own-env-t}()} otherwise.
-\end{itemize}
 If neither of these expressions is valid, the program is ill-formed.
 \item \exposid{environment} with \tcode{Environment(\exposid{own-env})} if that expression is
 valid, otherwise \tcode{Environment(get_env(\exposid{rcvr}))}
 if this expression is valid, otherwise \tcode{Environment()}.
 If neither of these expressions is valid, the program is ill-formed.
+\end{itemize}
 \end{itemdescr}
 
 \indexlibrarydtor{task::\exposid{state}}%