net/can/af_can.c: Change del_timer to del_timer_sync

This is important for SMP platform to check if timer function is
executing on other CPU with deleting the timer.

Signed-off-by: Rajan Aggarwal <Rajan Aggarwal rajan.aggarwal85@gmail.com>
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/can/af_can.c

@@ -857,7 +857,7 @@ static __exit void can_exit(void)
 	struct net_device *dev;
 
 	if (stats_timer)
-		del_timer(&can_stattimer);
+		del_timer_sync(&can_stattimer);
 
 	can_remove_proc();