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

commit a135a1b 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>

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c

@@ -1434,7 +1434,8 @@ amdgpu_dm_update_connector_after_detect(struct amdgpu_dm_connector *aconnector)
 
 			drm_connector_update_edid_property(connector,
 							   aconnector->edid);
-			drm_add_edid_modes(connector, aconnector->edid);
+			aconnector->num_modes = drm_add_edid_modes(connector, aconnector->edid);
+			drm_connector_list_update(connector);
 
 			if (aconnector->dc_link->aux_mode)
 				drm_dp_cec_set_edid(&aconnector->dm_dp_aux.aux,