leds: leds-cobalt-qube: Use devm_led_classdev_register
leds: leds-cobalt-qube: Use devm_led_classdev_register

Use resource-managed function devm_led_classdev_register instead
of led_classdev_register to make the error-path simpler.

To be compatible with the change, goto is replaced with direct
return, unneeded label err_null is dropped and unnecessary variable
retval is removed. Also, remove redundant cobalt_qube_led_remove.

Signed-off-by: Vaishali Thakkar <d326f246a6487957dd2597537de070b545202a3d@gmail.com>
Signed-off-by: Jacek Anaszewski <6a953cb1c532e2765a42e582ecefff5a01106214@samsung.com>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs