Fix a reference to [[inFlightCloseRequest]]

It's on WritableStream, not WritableStreamDefaultController.

Author: lucacasonato

index.bs

@@ -4456,8 +4456,7 @@ the {{WritableStream}}'s public API.
  performs the following steps:
 
  1. If |stream|.[=WritableStream/[[inFlightWriteRequest]]=] is undefined and
-    |stream|.[=WritableStream/[[controller]]=].[=WritableStream/[[inFlightCloseRequest]]=] is
-    undefined, return false.
+    |stream|.[=WritableStream/[[inFlightCloseRequest]]=] is undefined, return false.
  1. Return true.
 </div>
 
@@ -7429,6 +7428,7 @@ Jason Orendorff,
 Jeffrey Yasskin,
 Jens Nockert,
 Lennart Grahl,
+Luca Casonato,
 Mangala Sadhu Sangeet Singh Khalsa,
 Marcos Caceres,
 Marvin Hagemeister,