staging: r8188eu: always cancel blink_work before WPS blinking

In rtw_led_control, we can always cancel a running blink worker when we
start WPS blinking.

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

Tested-by: Michael Straube <straube.linux@gmail.com>
Signed-off-by: Martin Kaiser <martin@kaiser.cx>
Link: https://lore.kernel.org/r/20220905200146.82259-4-martin@kaiser.cx


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