rcu: Remove "extern" from function declarations in include/linux/*rcu*.h

Function prototypes don't need to have the "extern" keyword since this
is the default behavior. Its explicit use is redundant.  This commit
therefore removes them.

Signed-off-by: Teodora Baluta <teobaluta@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
diff --git a/include/linux/rcutree.h b/include/linux/rcutree.h
index 4b9c815..72137ee 100644
--- a/include/linux/rcutree.h
+++ b/include/linux/rcutree.h
@@ -30,9 +30,9 @@
 #ifndef __LINUX_RCUTREE_H
 #define __LINUX_RCUTREE_H
 
-extern void rcu_note_context_switch(int cpu);
-extern int rcu_needs_cpu(int cpu, unsigned long *delta_jiffies);
-extern void rcu_cpu_stall_reset(void);
+void rcu_note_context_switch(int cpu);
+int rcu_needs_cpu(int cpu, unsigned long *delta_jiffies);
+void rcu_cpu_stall_reset(void);
 
 /*
  * Note a virtualization-based context switch.  This is simply a
@@ -44,9 +44,9 @@
 	rcu_note_context_switch(cpu);
 }
 
-extern void synchronize_rcu_bh(void);
-extern void synchronize_sched_expedited(void);
-extern void synchronize_rcu_expedited(void);
+void synchronize_rcu_bh(void);
+void synchronize_sched_expedited(void);
+void synchronize_rcu_expedited(void);
 
 void kfree_call_rcu(struct rcu_head *head, void (*func)(struct rcu_head *rcu));
 
@@ -71,25 +71,25 @@
 	synchronize_sched_expedited();
 }
 
-extern void rcu_barrier(void);
-extern void rcu_barrier_bh(void);
-extern void rcu_barrier_sched(void);
+void rcu_barrier(void);
+void rcu_barrier_bh(void);
+void rcu_barrier_sched(void);
 
 extern unsigned long rcutorture_testseq;
 extern unsigned long rcutorture_vernum;
-extern long rcu_batches_completed(void);
-extern long rcu_batches_completed_bh(void);
-extern long rcu_batches_completed_sched(void);
+long rcu_batches_completed(void);
+long rcu_batches_completed_bh(void);
+long rcu_batches_completed_sched(void);
 
-extern void rcu_force_quiescent_state(void);
-extern void rcu_bh_force_quiescent_state(void);
-extern void rcu_sched_force_quiescent_state(void);
+void rcu_force_quiescent_state(void);
+void rcu_bh_force_quiescent_state(void);
+void rcu_sched_force_quiescent_state(void);
 
-extern void exit_rcu(void);
+void exit_rcu(void);
 
-extern void rcu_scheduler_starting(void);
+void rcu_scheduler_starting(void);
 extern int rcu_scheduler_active __read_mostly;
 
-extern bool rcu_is_watching(void);
+bool rcu_is_watching(void);
 
 #endif /* __LINUX_RCUTREE_H */