W1: fix memset size error

The size argument passed to memset is wrong.

Signed-off-by Li Zefan <lizf@cn.fujitsu.com>
Acked-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/w1/masters/ds2490.c

@@ -233,7 +233,7 @@ static int ds_recv_status_nodump(struct ds_device *dev, struct ds_status *st,
 {
 	int count, err;
 
-	memset(st, 0, sizeof(st));
+	memset(st, 0, sizeof(*st));
 
 	count = 0;
 	err = usb_bulk_msg(dev->udev, usb_rcvbulkpipe(dev->udev, dev->ep[EP_STATUS]), buf, size, &count, 100);