staging/rts_pstor: fix Polling thread wakeups CPU

RealTek PCI-E Card Reader rts_pstor driver causes CPU wakeup very
frequently, thatt's bad for power consumption.
Signed-off-by: NCho, Yu-Chen <acho@novell.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

drivers/staging/rts_pstor/rtsx.c

@@ -594,7 +594,9 @@ static int rtsx_polling_thread(void *__dev)
 	wait_timeout((delay_use + 5) * 1000);
 
 	for (;;) {
-		wait_timeout(POLLING_INTERVAL);
+
+		set_current_state(TASK_INTERRUPTIBLE);
+		schedule_timeout(POLLING_INTERVAL);
 
 		/* lock the device pointers */
 		mutex_lock(&(dev->dev_mutex));