ACPI: asus-laptop: Fix failure exits

> Subject         : drivers/misc/asus-laptop.c:*: error: 'struct led_classdev' has no member named 'class_dev'
> References      : http://lkml.org/lkml/2007/7/22/299


> Submitter       : Gabriel C <nix.or.die@googlemail.com>

Fallout from f8a7c6fe.  However, looking
at it shows that checks done in ASUS_LED_UNREGISTER() can't trigger
at all (we never get to asus_led_exit() if registration fails) and
if that registration fails, we actually leak stuff.  IOW, it's worse
than just replacing class_dev with dev in there - the tests themselves
had been papering over the lousy cleanup logics.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Len Brown <len.brown@intel.com>