staging: r8188eu: cancel blink_work before tx/rx blinking

Cancel blink_work before we start tx/rx blinking. Another worker will be
scheduled after the state variables are updated.

Tested-by: Philipp Hortmann <philipp.g.hortmann@gmail.com> # Edimax N150
Signed-off-by: Martin Kaiser <martin@kaiser.cx>
Link: https://lore.kernel.org/r/20220911145122.15444-6-martin@kaiser.cx


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