cyclic xcall: use smp_no_rendevous_barrier as setup function parameter
cyclic xcall: use smp_no_rendevous_barrier as setup function parameter

In this case we call target function only on a single CPU and do not
need any synchronization at the setup stage.

It's a bit non-obvious but setup function of NULL means that
smp_rendezvous_cpus waits for all CPUs to arrive at the rendezvous
point, but without doing any actual setup.  While using
smp_no_rendevous_barrier means that each CPU proceeds on its own
schedule without any synchronization whatsoever.

MFC after:	3 weeks

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