xhci: Add a few missing checks for disconnected devices
One of the reworks of qemu's usb core made changes to usb-port's disconnect
handling. Now ports with a device will always have a non 0 dev member, but
if the device is not attached (which is possible with usb redirection),
dev->attached will be 0.
So supplement all checks for dev to also check dev->attached, and add an
extra check in a path where a device check was completely missing.
This fixes various crashes (asserts triggering) I've been seeing when xhci
attached usb devices get disconnected at the wrong time.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>