rcu: Mark init-time-only rcu_bootup_announce() as __init

Because rcu_bootup_announce() is used only at boot time, mark it
as __init, presumably so that its memory can be reclaimed.
Suggested-by: NJoe Perches <joe@perches.com>
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: mathieu.desnoyers@polymtl.ca
Cc: josh@joshtriplett.org
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
Cc: rostedt@goodmis.org
Cc: Valdis.Kletnieks@vt.edu
Cc: dhowells@redhat.com
LKML-Reference: <20091111192806.GA10073@linux.vnet.ibm.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

kernel/rcutree_plugin.h

@@ -33,7 +33,7 @@ DEFINE_PER_CPU(struct rcu_data, rcu_preempt_data);
 /*
  * Tell them what RCU they are running.
  */
-static void rcu_bootup_announce(void)
+static void __init rcu_bootup_announce(void)
 {
 	printk(KERN_INFO
 	       "Experimental preemptable hierarchical RCU implementation.\n");
@@ -481,7 +481,7 @@ void exit_rcu(void)
 /*
  * Tell them what RCU they are running.
  */
-static void rcu_bootup_announce(void)
+static void __init rcu_bootup_announce(void)
 {
 	printk(KERN_INFO "Hierarchical RCU implementation.\n");
 }