kmemtrace, rcu: fix rcu_tree_trace.c data structure dependencies

Impact: cleanup

We want to remove rcutree internals from the public rcutree.h file for
upcoming kmemtrace changes - but kernel/rcutree_trace.c depends on them.

Introduce kernel/rcutree.h for internal definitions. (Probably all
the other data types from include/linux/rcutree.h could be
moved here too - except rcu_data.)

Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro>
Cc: paulmck@linux.vnet.ibm.com
LKML-Reference: <1237898630.25315.83.camel@penberg-laptop>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/rcutree.c b/kernel/rcutree.c
index a2015ed..7f32669 100644
--- a/kernel/rcutree.c
+++ b/kernel/rcutree.c
@@ -72,11 +72,11 @@
 	.n_force_qs_ngp = 0, \
 }
 
-static struct rcu_state rcu_state = RCU_STATE_INITIALIZER(rcu_state);
-static DEFINE_PER_CPU(struct rcu_data, rcu_data);
+struct rcu_state rcu_state = RCU_STATE_INITIALIZER(rcu_state);
+DEFINE_PER_CPU(struct rcu_data, rcu_data);
 
-static struct rcu_state rcu_bh_state = RCU_STATE_INITIALIZER(rcu_bh_state);
-static DEFINE_PER_CPU(struct rcu_data, rcu_bh_data);
+struct rcu_state rcu_bh_state = RCU_STATE_INITIALIZER(rcu_bh_state);
+DEFINE_PER_CPU(struct rcu_data, rcu_bh_data);
 
 /*
  * Increment the quiescent state counter.