sysctl extern cleanup: C_A_D

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

Move C_A_D extern variable declaration to linux/reboot.h

Signed-off-by: Dave Young <hidave.darkstar@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/reboot.h b/include/linux/reboot.h
index 988e55f..3005d5a 100644
--- a/include/linux/reboot.h
+++ b/include/linux/reboot.h
@@ -64,6 +64,7 @@
 extern void kernel_halt(void);
 extern void kernel_power_off(void);
 
+extern int C_A_D; /* for sysctl */
 void ctrl_alt_del(void);
 
 #define POWEROFF_CMD_PATH_LEN	256