dm: core: Fix uclass_probe_all to really probe all devices

uclass_probe_all uses uclass_first_device/uclass_next_device assigning
the return value.

The interface for getting meaningful error is
uclass_first_device_check/uclass_next_device_check, use it.

Also do not stop iteration when an error is encountered. Probing all
devices includes those that happen to be after a failing device in the
uclass order.

Fixes: a59153dfeb ("dm: core: add function uclass_probe_all() to probe all devices")
Signed-off-by: Michal Suchanek <msuchanek@suse.de>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/core/uclass.c b/drivers/core/uclass.c
index 08d9ed8..a591e22 100644
--- a/drivers/core/uclass.c
+++ b/drivers/core/uclass.c
@@ -799,20 +799,18 @@
 int uclass_probe_all(enum uclass_id id)
 {
 	struct udevice *dev;
-	int ret;
+	int ret, err;
 
-	ret = uclass_first_device(id, &dev);
-	if (ret || !dev)
-		return ret;
+	err = uclass_first_device_check(id, &dev);
 
 	/* Scanning uclass to probe all devices */
 	while (dev) {
-		ret = uclass_next_device(&dev);
+		ret = uclass_next_device_check(&dev);
 		if (ret)
-			return ret;
+			err = ret;
 	}
 
-	return 0;
+	return err;
 }
 
 int uclass_id_count(enum uclass_id id)