Description: Bluetooth: verify AMP hci_chan before amp_destroy
References:
 https://sites.google.com/view/syzscope/kasan-use-after-free-read-in-hci_send_acl
 https://syzkaller.appspot.com/bug?id=2e1943a94647f7732dd6fc60368642d6e8dc91b1
Notes:
 bwh: Appears to have been introduced before 4.9.
Bugs:
upstream: released (5.13-rc1) [5c4c8c9544099bb9043a10a5318130a943e32fc3]
5.10-upstream-stable: released (5.10.37) [1d7bd87a2c8d264ca3e5c9ba6f3eafc23e994028]
4.19-upstream-stable: released (4.19.191) [75e26178e26f910f7f26c79c2824b726eecf0dfb]
4.9-upstream-stable: released (4.9.269) [31f20a6e73663c8ac3c625aa6b24cbdc8541c674]
sid: released (5.10.38-1)
4.19-buster-security: released (4.19.194-1)
4.9-stretch-security: released (4.9.272-1)