unregister_console  116 include/linux/console.h extern int unregister_console(struct console *);
unregister_console 1620 kernel/kgdb.c  			unregister_console(&kgdbcons);
unregister_console 1210 kernel/printk.c 		unregister_console(bootconsole);
unregister_console 1287 kernel/printk.c 			return unregister_console(console_drivers);