netfilter: xt_IDLETIMER: clean up some indenting

These lines were indented wrong so Smatch complained.
net/netfilter/xt_IDLETIMER.c:81 idletimer_tg_show() warn: inconsistent indenting
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

net/netfilter/xt_IDLETIMER.c

@@ -78,8 +78,7 @@ static ssize_t idletimer_tg_show(struct device *dev,
 			time_diff = ktimespec.tv_sec;
 		} else {
 			expires = timer->timer.expires;
-			time_diff = jiffies_to_msecs(
-						expires - jiffies) / 1000;
+			time_diff = jiffies_to_msecs(expires - jiffies) / 1000;
 		}
 	}