sysctl extern cleanup: rcu

Extern declarations in sysctl.c should be moved to their own header file,
and then include them in relavant .c files.

Move rcutorture_runnable extern declaration to linux/rcupdate.h

Signed-off-by: Dave Young <hidave.darkstar@gmail.com>
Acked-by: Josh Triplett <josh@joshtriplett.org>
Reviewed-by: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/linux/rcupdate.h

@@ -41,6 +41,10 @@
 #include <linux/lockdep.h>
 #include <linux/completion.h>
 
+#ifdef CONFIG_RCU_TORTURE_TEST
+extern int rcutorture_runnable; /* for sysctl */
+#endif /* #ifdef CONFIG_RCU_TORTURE_TEST */
+
 /**
  * struct rcu_head - callback structure for use with RCU
  * @next: next update requests in a list

kernel/sysctl.c

@@ -87,9 +87,6 @@ extern int sysctl_nr_open_min, sysctl_nr_open_max;
 #ifndef CONFIG_MMU
 extern int sysctl_nr_trim_pages;
 #endif
-#ifdef CONFIG_RCU_TORTURE_TEST
-extern int rcutorture_runnable;
-#endif /* #ifdef CONFIG_RCU_TORTURE_TEST */
 #ifdef CONFIG_BLOCK
 extern int blk_iopoll_enabled;
 #endif