make kernel_shutdown_prepare() static

kernel_shutdown_prepare() can now become static.
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Acked-by: Pavel Machek <pavel@ucw.cz>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/linux/reboot.h

@@ -59,8 +59,6 @@ extern void machine_crash_shutdown(struct pt_regs *);
  * Architecture independent implemenations of sys_reboot commands.
  */
 
-extern void kernel_shutdown_prepare(enum system_states state);
-
 extern void kernel_restart(char *cmd);
 extern void kernel_halt(void);
 extern void kernel_power_off(void);

kernel/sys.c

@@ -315,7 +315,7 @@ static void kernel_kexec(void)
 #endif
 }
 
-void kernel_shutdown_prepare(enum system_states state)
+static void kernel_shutdown_prepare(enum system_states state)
 {
 	blocking_notifier_call_chain(&reboot_notifier_list,
 		(state == SYSTEM_HALT)?SYS_HALT:SYS_POWER_OFF, NULL);