drm/radeon: possible buffer overflow

mainline inclusion
from mainline-v6.7-rc1
commit dd05484f99d16715a88eedfca363828ef9a4c2d4
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/I9R7JN
CVE: CVE-2023-52867

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=dd05484f99d16715a88eedfca363828ef9a4c2d4



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

Buffer 'afmt_status' of size 6 could overflow, since index 'afmt_idx' is
checked after access.

Fixes: 5cc4e5fc ("drm/radeon: Cleanup HDMI audio interrupt handling for evergreen")
Co-developed-by: Ivanov Mikhail <ivanov.mikhail1@huawei-partners.com>
Signed-off-by: Konstantin Meskhidze <konstantin.meskhidze@huawei.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Luo Gengkun <luogengkun@huaweicloud.com>