Bluetooth: virtio_bt: fix memory leak in virtbt_rx_handle()

Bluetooth: virtio_bt: fix memory leak in virtbt_rx_handle()

BugLink: https://bugs.launchpad.net/bugs/1959376
[ Upstream commit 1d0688421449718c6c5f46e458a378c9b530ba18 ]

On the reception of packets with an invalid packet type, the memory of
the allocated socket buffers is never freed. Add a default case that frees
these to avoid a memory leak.

Fixes: afd2daa26c7a ("Bluetooth: Add support for virtio transport driver")
Signed-off-by: Soenke Huster <soenke.huster@eknoes.de>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Paolo Pisati <paolo.pisati@canonical.com>