When the registration fails, we need to release the memory we allocated.
Also we need to save the error from led_classdev_register and propagate
it up, else we'll return success, even if we failed.
Signed-off-by: NRiku Voipio <riku.voipio@iki.fi>
Signed-off-by: NRichard Purdie <rpurdie@linux.intel.com>