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

drivers/staging/r8188eu/include/rtw_pwrctrl.h

@@ -61,7 +61,6 @@ enum { /*  for ips_mode */
 
 struct pwrctrl_priv {
 	struct semaphore lock;
-	volatile u8 cpwm_tog; /*  toggling */
 
 	u8	pwr_mode;
 	u8	smart_ps;