net: cdc-phonet: fix data-interface release on probe failure

stable inclusion
from stable-5.10.27
commit 421e0d731070fb497212ba929df3623cfce4561d
bugzilla: 51493

--------------------------------

[ Upstream commit c79a7070 ]

Set the disconnected flag before releasing the data interface in case
netdev registration fails to avoid having the disconnect callback try to
deregister the never registered netdev (and trigger a WARN_ON()).

Fixes: 87cf6560 ("USB host CDC Phonet network interface driver")
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Chen Jun <chenjun102@huawei.com>
Acked-by:   Weilong Chen <chenweilong@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>