kexec jump: remove duplication of kexec_restart_prepare()

Call kernel_restart_prepare() in kernel_kexec() instead of duplicating the
code.

Signed-off-by: Huang Ying <ying.huang@intel.com>
Acked-by: Pavel Machek <pavel@suse.cz>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
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 b93b541..988e55f 100644
--- a/include/linux/reboot.h
+++ b/include/linux/reboot.h
@@ -59,6 +59,7 @@
  * Architecture independent implemenations of sys_reboot commands.
  */
 
+extern void kernel_restart_prepare(char *cmd);
 extern void kernel_restart(char *cmd);
 extern void kernel_halt(void);
 extern void kernel_power_off(void);