rcutorture: Suppress boottime bad-sequence warnings

In normal production, an excessively long wait on a grace period
(synchronize_rcu(), for example) at boottime is often just as bad
as at any other time.  In fact, given the desire for fast boot, any
sort of long wait at boot is a bad idea.  However, heavy rcutorture
testing on large hyperthreaded systems can generate such long waits
during boot as a matter of course.  This commit therefore causes
the rcupdate.rcu_cpu_stall_suppress_at_boot kernel boot parameter to
suppress reporting of bootime bad-sequence warning due to excessively
long grace-period waits.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

kernel/rcu/rcutorture.c

@@ -1423,7 +1423,8 @@ rcu_torture_stats_print(void)
 	pr_alert("%s%s ", torture_type, TORTURE_FLAG);
 	pr_cont("rtc: %p %s: %lu tfle: %d rta: %d rtaf: %d rtf: %d ",
 		rcu_torture_current,
-		rcu_torture_current ? "ver" : "VER",
+		rcu_torture_current && !rcu_stall_is_suppressed_at_boot()
+			? "ver" : "VER",
 		rcu_torture_current_version,
 		list_empty(&rcu_torture_freelist),
 		atomic_read(&n_rcu_torture_alloc),