staging: most: i2c: prevent division by zero

This prevents division by zero scan_rate.

The zero scan_rate does not need any special action as it actually means
"never poll again".
Signed-off-by: Andrey Shvetsov <andrey.shvetsov@k2l.de>
Signed-off-by: Christian Gromm <christian.gromm@microchip.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/most/i2c/i2c.c

@@ -252,7 +252,7 @@ static void pending_rx_work(struct work_struct *work)
 	do_rx_work(dev);
 
 	if (dev->polling_mode) {
-		if (dev->is_open[CH_RX])
+		if (dev->is_open[CH_RX] && scan_rate)
 			schedule_delayed_work(&dev->rx.dwork,
 					      msecs_to_jiffies(MSEC_PER_SEC
 							       / scan_rate));