->aio_read and ->aio_write removed

no remaining users

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/Documentation/filesystems/porting b/Documentation/filesystems/porting
index 4006483..e69274d 100644
--- a/Documentation/filesystems/porting
+++ b/Documentation/filesystems/porting
@@ -480,3 +480,6 @@
 [mandatory]
 	do _not_ use new_sync_{read,write} for ->read/->write; leave it NULL
 	instead.
+--
+[mandatory]
+	->aio_read/->aio_write are gone.  Use ->read_iter/->write_iter.