Sometimes multiple packets are received and we were assuming it was
some repeated requests due to slow ack. We can ack packets first.

It was also dropping some perfectly valid packets and we should process
them all. For instance, lldb frontend sometimes send multiple packets
at a the same time and expects them to be handled.
Signed-off-by: Rémi Bernon <rbernon@codeweavers.com>
Signed-off-by: Alexandre Julliard <julliard@winehq.org>