rcu: Move rcu_implicit_dynticks_qs() to ->gp_seq

This commit makes rcu_implicit_dynticks_qs() use ->gp_seq, with the
exception of tracing, which will be converted later.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

kernel/rcu/tree.c

@@ -1178,7 +1178,7 @@ static int rcu_implicit_dynticks_qs(struct rcu_data *rdp)
 	ruqp = per_cpu_ptr(&rcu_dynticks.rcu_urgent_qs, rdp->cpu);
 	if (time_after(jiffies, rdp->rsp->gp_start + jtsq) &&
 	    READ_ONCE(rdp->rcu_qs_ctr_snap) != per_cpu(rcu_dynticks.rcu_qs_ctr, rdp->cpu) &&
-	    READ_ONCE(rdp->gpnum) == rnp->gpnum && !rdp->gpwrap) {
+	    rcu_seq_current(&rdp->gp_seq) == rnp->gp_seq && !rdp->gpwrap) {
 		trace_rcu_fqs(rdp->rsp->name, rdp->gpnum, rdp->cpu, TPS("rqc"));
 		rcu_gpnum_ovf(rnp, rdp);
 		return 1;