staging: r8188eu: remove unused variable cpwm_tog

cpwm_tog in struct pwrctrl_priv is not used. Remove it.

Signed-off-by: Martin Kaiser <martin@kaiser.cx>
Link: https://lore.kernel.org/r/20210913185110.3065-8-martin@kaiser.cx


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