Export sysboml for bbox to use.

ascend inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I4D63I
CVE: NA

-------------------------------------------------

Export console_flush_on_panic for bbox to use.
Signed-off-by: NXu Qiang <xuqiang36@huawei.com>
Signed-off-by: NFang Lijun <fanglijun3@huawei.com>
Reviewed-by: NDing Tianhong <dingtianhong@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>
Reviewed-by: NWeilong Chen <chenweilong@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

kernel/printk/printk.c

@@ -2647,6 +2647,7 @@ void console_flush_on_panic(enum con_flush_mode mode)
 	}
 	console_unlock();
 }
+EXPORT_SYMBOL(console_flush_on_panic);
 
 /*
  * Return the console tty driver structure and its associated index