ACPI: video: check for error while searching for backlight device parent

stable inclusion
from stable-v4.19.306
commit 556f02699d33c1f40b1b31bd25828ce08fa165d8
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/I9Q9CJ
CVE: CVE-2023-52693

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=556f02699d33c1f40b1b31bd25828ce08fa165d8



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

[ Upstream commit ccd45faf4973746c4f30ea41eec864e5cf191099 ]

If acpi_get_parent() called in acpi_video_dev_register_backlight()
fails, for example, because acpi_ut_acquire_mutex() fails inside
acpi_get_parent), this can lead to incorrect (uninitialized)
acpi_parent handle being passed to acpi_get_pci_dev() for detecting
the parent pci device.

Check acpi_get_parent() result and set parent device only in case of success.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Fixes: 9661e92c ("acpi: tie ACPI backlight devices to PCI devices if possible")
Signed-off-by: Nikita Kiryushin <kiryushin@ancud.ru>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Yu Liao <liaoyu15@huawei.com>