staging/asus_oled fixed linebreak and printk issue

fixed a linebreak within an error message string coding style
issue reported by checkpatch.pl and dev_err format parameters

Signed-off-by: Matthias Schid <aircrach115@gmail.com>
Signed-off-by: Stefan Huber <steffhip@googlemail.com>
Signed-off-by: Simon Puels <simon.puels@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>