of: overlay: do not break notify on NOTIFY_{OK|STOP}

[ Upstream commit 5f756a2eaa ]

We should not break overlay notifications on NOTIFY_{OK|STOP}
otherwise we might break on the first fragment. We should only stop
notifications if a *real* errno is returned by one of the listeners.

Fixes: a1d19bd4cf ("of: overlay: pr_err from return NOTIFY_OK to overlay apply/remove")
Signed-off-by: Nuno Sá <nuno.sa@analog.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20220420130205.89435-1-nuno.sa@analog.com
Signed-off-by: Sasha Levin <sashal@kernel.org>

drivers/of/overlay.c

@@ -170,9 +170,7 @@ static int overlay_notify(struct overlay_changeset *ovcs,
 
 		ret = blocking_notifier_call_chain(&overlay_notify_chain,
 						   action, &nd);
-		if (ret == NOTIFY_OK || ret == NOTIFY_STOP)
-			return 0;
-		if (ret) {
+		if (notifier_to_errno(ret)) {
 			ret = notifier_to_errno(ret);
 			pr_err("overlay changeset %s notifier error %d, target: %pOF\n",
 			       of_overlay_action_name[action], ret, nd.target);