rcu: Make rcu_is_cpu_rrupt_from_idle helper functions static

Both rcutiny and rcutree define a helper function named
rcu_is_cpu_rrupt_from_idle(), each used exactly once, later in the
same file.  This commit therefore declares these helper functions static.

Signed-off-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

kernel/rcutiny.c

diff --git a/kernel/rcutiny.c b/kernel/rcutiny.c
index e7dce58..9f72a0f 100644
--- a/kernel/rcutiny.c
+++ b/kernel/rcutiny.c
@@ -193,7 +193,7 @@
  * interrupts don't count, we must be running at the first interrupt
  * level.
  */
-int rcu_is_cpu_rrupt_from_idle(void)
+static int rcu_is_cpu_rrupt_from_idle(void)
 {
 	return rcu_dynticks_nesting <= 1;
 }

kernel/rcutree.c

diff --git a/kernel/rcutree.c b/kernel/rcutree.c
index e441b77..cceda76 100644
--- a/kernel/rcutree.c
+++ b/kernel/rcutree.c
@@ -727,7 +727,7 @@
  * interrupt from idle, return true.  The caller must have at least
  * disabled preemption.
  */
-int rcu_is_cpu_rrupt_from_idle(void)
+static int rcu_is_cpu_rrupt_from_idle(void)
 {
 	return __get_cpu_var(rcu_dynticks).dynticks_nesting <= 1;
 }