macintosh: Use of_node_name_{eq, prefix} for node name comparisons

Convert string compares of DT node names to use of_node_name_{eq,prefix}
helpers instead. This removes direct access to the node name pointer.

This changes a single case insensitive node name comparison to case
sensitive for "ata4". This is the only instance of a case insensitive
comparison for all the open coded node name comparisons on powerpc.
Searching the commit history, there doesn't appear to be any reason for
it to be case insensitive.

A couple of open coded iterating thru the child node names are converted
to use for_each_child_of_node() instead.

Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
diff --git a/drivers/macintosh/rack-meter.c b/drivers/macintosh/rack-meter.c
index 1f29d24..3940e2a 100644
--- a/drivers/macintosh/rack-meter.c
+++ b/drivers/macintosh/rack-meter.c
@@ -376,18 +376,19 @@ static int rackmeter_probe(struct macio_dev* mdev,
 	pr_debug("rackmeter_probe()\n");
 
 	/* Get i2s-a node */
-	while ((i2s = of_get_next_child(mdev->ofdev.dev.of_node, i2s)) != NULL)
-	       if (strcmp(i2s->name, "i2s-a") == 0)
-		       break;
+	for_each_child_of_node(mdev->ofdev.dev.of_node, i2s)
+		if (of_node_name_eq(i2s, "i2s-a"))
+			break;
+
 	if (i2s == NULL) {
 		pr_debug("  i2s-a child not found\n");
 		goto bail;
 	}
 	/* Get lightshow or virtual sound */
-	while ((np = of_get_next_child(i2s, np)) != NULL) {
-	       if (strcmp(np->name, "lightshow") == 0)
+	for_each_child_of_node(i2s, np) {
+	       if (of_node_name_eq(np, "lightshow"))
 		       break;
-	       if ((strcmp(np->name, "sound") == 0) &&
+	       if (of_node_name_eq(np, "sound") &&
 		   of_get_property(np, "virtual", NULL) != NULL)
 		       break;
 	}