rcu: Fix comparison sense in rcu_needs_cpu()

Commit c0f4dfd4 (rcu: Make RCU_FAST_NO_HZ take advantage of numbered
callbacks) introduced a bug that can result in excessively long grace
periods.  This bug reverse the senes of the "if" statement checking
for lazy callbacks, so that RCU takes a lazy approach when there are
in fact non-lazy callbacks.  This can result in excessive boot, suspend,
and resume times.

This commit therefore fixes the sense of this "if" statement.
Reported-by: NBorislav Petkov <bp@alien8.de>
Reported-by: NBjørn Mork <bjorn@mork.no>
Reported-by: NJoerg Roedel <joro@8bytes.org>
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: NBjørn Mork <bjorn@mork.no>
Tested-by: NJoerg Roedel <joro@8bytes.org>

kernel/rcutree_plugin.h

@@ -1667,7 +1667,7 @@ int rcu_needs_cpu(int cpu, unsigned long *dj)
 	rdtp->last_accelerate = jiffies;
 
 	/* Request timer delay depending on laziness, and round. */
-	if (rdtp->all_lazy) {
+	if (!rdtp->all_lazy) {
 		*dj = round_up(rcu_idle_gp_delay + jiffies,
 			       rcu_idle_gp_delay) - jiffies;
 	} else {