of/flattree: Drop an uninteresting message to pr_debug level

This message looks like an error (which it isn't) when booting with a
flattened device tree.  Remove the message from normal kernel builds.

Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
diff --git a/fs/proc/proc_devtree.c b/fs/proc/proc_devtree.c
index d9396a4..927cbd1 100644
--- a/fs/proc/proc_devtree.c
+++ b/fs/proc/proc_devtree.c
@@ -233,7 +233,7 @@
 		return;
 	root = of_find_node_by_path("/");
 	if (root == NULL) {
-		printk(KERN_ERR "/proc/device-tree: can't find root\n");
+		pr_debug("/proc/device-tree: can't find root\n");
 		return;
 	}
 	proc_device_tree_add_node(root, proc_device_tree);