ipvs: Use schedule_timeout_interruptible() instead of msleep_interruptible()

So that kthread_stop() can wake up the thread and we don't have to wait one
second in the worst case for the daemon to actually stop.
Signed-off-by: Sven Wegener <sven.wegener@stealer.net>
Acked-by: Simon Horman <horms@verge.net.au>

net/ipv4/ipvs/ip_vs_sync.c

@@ -742,7 +742,7 @@ static int sync_thread_master(void *data)
 			ip_vs_sync_buff_release(sb);
 		}
 
-		msleep_interruptible(1000);
+		schedule_timeout_interruptible(HZ);
 	}
 
 	/* clean up the sync_buff queue */