The '-i AIO' option was accidentally placed after '-n' and '-t'. Move it
after '--flush-interval'.

Signed-off-by: Julia Suvorova <jusual@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20200205163008.204493-1-jusual@redhat.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>