of: Migrate of_find_node_by_name() users to for_each_node_by_name()

There are a bunch of users open coding the for_each_node_by_name() by
calling of_find_node_by_name() directly instead of using the macro. This
is getting in the way of some cleanups, and the possibility of removing
of_find_node_by_name() entirely. Clean it up so that all the users are
consistent.

Signed-off-by: Grant Likely <grant.likely@linaro.org>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Takashi Iwai <tiwai@suse.de>
diff --git a/drivers/edac/cell_edac.c b/drivers/edac/cell_edac.c
index 374b57f..a12c855 100644
--- a/drivers/edac/cell_edac.c
+++ b/drivers/edac/cell_edac.c
@@ -134,8 +134,7 @@
 	int				j;
 	u32				nr_pages;
 
-	for (np = NULL;
-	     (np = of_find_node_by_name(np, "memory")) != NULL;) {
+	for_each_node_by_name(np, "memory") {
 		struct resource r;
 
 		/* We "know" that the Cell firmware only creates one entry