[exec.as.awaitable] Move "except that..." sentence fragment up

Author: tkoeppe

source/exec.tex

@@ -5353,7 +5353,9 @@
 where \tcode{p} is an lvalue,
 \tcode{Expr} names the type \tcode{decltype((expr))} and
 \tcode{Promise} names the type \tcode{decay_t<decltype((p))>},
-\tcode{as_awaitable(expr, p)} is expression-equivalent to:
+\tcode{as_awaitable(expr, p)} is expression-equivalent to,
+except that the evaluations of \tcode{expr} and \tcode{p}
+are indeterminately sequenced:
 \begin{itemize}
 \item
 \tcode{expr.as_awaitable(p)} if that expression is well-formed.
@@ -5379,8 +5381,6 @@
 \item
 Otherwise, \tcode{(void(p), expr)}.
 \end{itemize}
-except that the evaluations of \tcode{expr} and \tcode{p}
-are indeterminately sequenced.
 
 \rSec2[exec.with.awaitable.senders]{\tcode{execution::with_awaitable_senders}}