media: pvrusb2: fix memory leak in pvr_probe

mainline inclusion
from mainline-v6.1-rc1
commit 945a9a8e
category: bugfix
bugzilla: 187857, https://gitee.com/src-openeuler/kernel/issues/I5X9DT
CVE: CVE-2022-3577

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=945a9a8e448b65bec055d37eba58f711b39f66f0



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The error handling code in pvr2_hdw_create forgets to unregister the
v4l2 device. When pvr2_hdw_create returns back to pvr2_context_create,
it calls pvr2_context_destroy to destroy context, but mp->hdw is NULL,
which leads to that pvr2_hdw_destroy directly returns.

Fix this by adding v4l2_device_unregister to decrease the refcount of
usb interface.

Reported-by:  <syzbot+77b432d57c4791183ed4@syzkaller.appspotmail.com>
Signed-off-by: Dongliang Mu <mudongliangabcd@gmail.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
Signed-off-by: Li Huafei <lihuafei1@huawei.com>
Reviewed-by: Kuohai Xu <xukuohai@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>