drm/amd/display: Fix memory leaks in S3 resume

drm/amd/display: Fix memory leaks in S3 resume

commit a135a1b4c4db1f3b8cbed9676a40ede39feb3362 upstream.

EDID parsing in S3 resume pushes new display modes
to probed_modes list but doesn't consolidate to actual
mode list. This creates a race condition when
amdgpu_dm_connector_ddc_get_modes() re-initializes the
list head without walking the list and results in  memory leak.

Bug: https://bugzilla.kernel.org/show_bug.cgi?id=209987
Acked-by: Harry Wentland <harry.wentland@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Signed-off-by: Stylon Wang <stylon.wang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>