[PATCH 2/2] of: Add check to of_scan_flat_dt() before accessing initial_boot_params

[Tobias Wolf <t.wolf@xxxxxxxxx>]

An empty __dtb_start to __dtb_end section might result in initial_boot_params 
being null for arch/mips/ralink. This showed that the boot process hangs 
indefinitely in of_scan_flat_dt().

Signed-off-by: Tobias Wolf <dev-NTEO@xxxxxxxxx>
---
--- a/drivers/of/fdt.c
+++ b/drivers/of/fdt.c
@@ -628,6 +628,9 @@
 				     void *data),
 			   void *data)
 {
+	if (!initial_boot_params)
+		return;
+
 	const void *blob = initial_boot_params;
 	const char *pathp;
 	int offset, rc = 0, depth = -1;