Merge branch 'urgent-for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu

Pull RCU warning removal from Paul McKenney:
 "A single commit that fixes an embarrassing bug discussed here:

      https://lore.kernel.org/lkml/20200125131425.GB16136@zn.tnic/

  which apparently also affects smaller systems"

[ This was sent to Ingo, but since I see the issue on the laptop I use for
  testing during the merge window, I'm doing the pull directly     - Linus ]

* 'urgent-for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu:
  rcu: Forgive slow expedited grace periods at boot time

kernel/rcu/tree_exp.h

@@ -508,7 +508,6 @@ static void synchronize_rcu_expedited_wait(void)
 				tick_dep_set_cpu(cpu, TICK_DEP_BIT_RCU_EXP);
 			}
 		}
-		WARN_ON_ONCE(1);
 	}
 
 	for (;;) {