hw/usb/hcd-xhci: Unmap canceled packet

hw/usb/hcd-xhci: Unmap canceled packet

When the Stop Endpoint Command is received, packets running
asynchronously are canceled and then all packets are cleaned up. Packets
running asynchronously hold the DMA mapping so cleaning the packets leak
the mapping. Remove the mapping after canceling packets to fix the leak.

Fixes: 62c6ae04cf43 ("xhci: Initial xHCI implementation")
Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-ID: <20250418-xhc-v1-1-bb32dab6a67e@daynix.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>