rcu: Summarize expedited RCU CPU stall warnings during CSD-lock stalls

rcu: Summarize expedited RCU CPU stall warnings during CSD-lock stalls

During CSD-lock stalls, the additional information output by expedited
RCU CPU stall warnings is usually redundant, flooding the console for
not good reason.  However, this has been the way things work for a few
years.  This commit therefore uses rcutree.csd_lock_suppress_rcu_stall
kernel boot parameter that causes expedited RCU CPU stall warnings to
be abbreviated to a single line when there is at least one CPU that has
been stuck waiting for CSD lock for more than five seconds.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Neeraj Upadhyay <neeraj.upadhyay@kernel.org>