of: use kbasename instead of open coding

Several places in DT code open code the equivalent of kbasename.
Replace them.

The behavior for root nodes in node_name_cmp will be slightly different.
Instead of comparing "/", "" will be compared. The comparison will be
the same.

Reviewed-by: Andy Shevchenko <andy.shevhchenko@gmail.com>
Signed-off-by: Rob Herring <robh@kernel.org>
diff --git a/drivers/of/platform.c b/drivers/of/platform.c
index 71fecc2..8f73413 100644
--- a/drivers/of/platform.c
+++ b/drivers/of/platform.c
@@ -99,7 +99,7 @@ static void of_device_make_bus_id(struct device *dev)
 
 		/* format arguments only used if dev_name() resolves to NULL */
 		dev_set_name(dev, dev_name(dev) ? "%s:%s" : "%s",
-			     strrchr(node->full_name, '/') + 1, dev_name(dev));
+			     kbasename(node->full_name), dev_name(dev));
 		node = node->parent;
 	}
 }