RCU: how to suppress warnings from rcu_assign_pointer?

[Stephen Hemminger <shemminger@vyatta.com>]

Gcc now generates warnings from rcu_assign_pointer when passed the
address of something for example:
	rcu_assign_pointer(dev_queue->qdisc, &noop_qdisc);
This warning is harmless and should be surpressed but there maybe
other cases where we want that Gcc warning.

I tried various combinations of in rcu_assign_pointer macro
  #pragma GCC diagnostic push
  #pragma GCC diagnostic ignored "-Wlogical-op"
  ...
  #pragma GCC diagnostic pop
but macro's and pragma's don't nest with the correct scope for
this.

Maybe some one with more Gcc foo and time to waste could take
a crack at it.