dtoc: Fix some minor errors

Fix some comments and a printf string which is incorrect.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/tools/dtoc/dtb_platdata.py b/tools/dtoc/dtb_platdata.py
index b1323ae..6cb1259 100644
--- a/tools/dtoc/dtb_platdata.py
+++ b/tools/dtoc/dtb_platdata.py
@@ -316,7 +316,8 @@
             total = na + ns
 
             if reg.type != fdt.TYPE_INT:
-                raise ValueError("Node '%s' reg property is not an int")
+                raise ValueError("Node '%s' reg property is not an int" %
+                                 node.name)
             if len(reg.value) % total:
                 raise ValueError("Node '%s' reg property has %d cells "
                         'which is not a multiple of na + ns = %d + %d)' %