staging: r8188eu: always cancel blink_work

In rtw_led_control, we can always cancel a running blink worker when we
start blinking because of no link.

The worker will be scheduled again and there's no point in having more
than one pending blink worker.

Signed-off-by: Martin Kaiser <martin@kaiser.cx>
Link: https://lore.kernel.org/r/20220822201329.95559-3-martin@kaiser.cx


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>