pkt_sched: fq: use proper locking in fq_dump_stats()

static int fq_dump_stats(struct Qdisc *sch, struct gnet_dump *d)

{

	struct fq_sched_data *q = qdisc_priv(sch);

	u64 now = ktime_get_ns();

	struct tc_fq_qd_stats st = {

		.gc_flows		= q->stat_gc_flows,

		.highprio_packets	= q->stat_internal_packets,

		.tcp_retrans		= q->stat_tcp_retrans,

		.throttled		= q->stat_throttled,

		.flows_plimit		= q->stat_flows_plimit,

		.pkts_too_long		= q->stat_pkts_too_long,

		.allocation_errors	= q->stat_allocation_errors,

		.flows			= q->flows,

		.inactive_flows		= q->inactive_flows,

		.throttled_flows	= q->throttled_flows,

		.time_next_delayed_flow	= q->time_next_delayed_flow - now,

	};

	struct tc_fq_qd_stats st;

	sch_tree_lock(sch);

	st.gc_flows		  = q->stat_gc_flows;

	st.highprio_packets	  = q->stat_internal_packets;

	st.tcp_retrans		  = q->stat_tcp_retrans;

	st.throttled		  = q->stat_throttled;

	st.flows_plimit		  = q->stat_flows_plimit;

	st.pkts_too_long	  = q->stat_pkts_too_long;

	st.allocation_errors	  = q->stat_allocation_errors;

	st.time_next_delayed_flow = q->time_next_delayed_flow - ktime_get_ns();

	st.flows		  = q->flows;

	st.inactive_flows	  = q->inactive_flows;

	st.throttled_flows	  = q->throttled_flows;

	st.pad			  = 0;

	sch_tree_unlock(sch);

	return gnet_stats_copy_app(d, &st, sizeof(st));

}