of: overlay: add resolver error prints

Applying overlay fails silently in case of an error. Add error prints.
Most notably the lack of symbols in the live tree is not reported.
Signed-off-by: Michal Suchanek <hramrach@gmail.com>
Signed-off-by: Rob Herring <robh@kernel.org>

drivers/of/resolver.c

@@ -315,6 +315,11 @@ int of_resolve_phandles(struct device_node *resolve)
 	phandle phandle, phandle_delta;
 	int err;
 
+	if (!resolve)
+		pr_err("%s: null node\n", __func__);
+	if (resolve && !of_node_check_flag(resolve, OF_DETACHED))
+		pr_err("%s: node %s not detached\n", __func__,
+			 resolve->full_name);
 	/* the resolve node must exist, and be detached */
 	if (!resolve || !of_node_check_flag(resolve, OF_DETACHED))
 		return -EINVAL;
@@ -371,6 +376,7 @@ int of_resolve_phandles(struct device_node *resolve)
 
 	/* we need to fixup, but no root symbols... */
 	if (!root_sym) {
+		pr_err("%s: no symbols in root of device tree.\n", __func__);
 		err = -EINVAL;
 		goto out;
 	}