staging: xillybus: fix format string usage

Makes sure format string cannot leak into device_create() call.
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/xillybus/xillybus_core.c

@@ -2054,7 +2054,7 @@ static int xillybus_init_chrdev(struct xilly_endpoint *endpoint,
 				       NULL,
 				       MKDEV(major, i),
 				       NULL,
-				       devname);
+				       "%s", devname);
 
 		if (IS_ERR(device)) {
 			pr_warn("xillybus: Failed to create %s "