[PATCH] kernel/sys.c: cleanups

- proper prototypes for the following functions:
  - ctrl_alt_del()  (in include/linux/reboot.h)
  - getrusage()     (in include/linux/resource.h)
- make the following needlessly global functions static:
  - kernel_restart_prepare()
  - kernel_kexec()

[akpm@osdl.org: compile fix]
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

arch/um/drivers/mconsole_kern.c

@@ -300,8 +300,6 @@ void mconsole_reboot(struct mc_request *req)
 	machine_restart(NULL);
 }
 
-extern void ctrl_alt_del(void);
-
 void mconsole_cad(struct mc_request *req)
 {
 	mconsole_reply(req, "", 0, 0);