printk: Constify name for add_preferred_console()

While adding a preferred console handling for serial_core for serial port
hardware based device addressing, Jiri suggested we constify name for
add_preferred_console(). The name gets copied anyways. This allows serial
core to add a preferred console using serial drv->dev_name without copying
it.

Note that constifying options causes changes all over the place because of
struct console for match().
Suggested-by: Jiri Slaby <jirislaby@kernel.org>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Link: https://lore.kernel.org/r/20231012064300.50221-2-tony@atomide.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

include/linux/console.h

@@ -347,7 +347,7 @@ enum con_flush_mode {
 	CONSOLE_REPLAY_ALL,
 };
 
-extern int add_preferred_console(char *name, const short idx, char *options);
+extern int add_preferred_console(const char *name, const short idx, char *options);
 extern void console_force_preferred_locked(struct console *con);
 extern void register_console(struct console *);
 extern int unregister_console(struct console *);

kernel/printk/printk.c

@@ -2404,7 +2404,7 @@ static void set_user_specified(struct console_cmdline *c, bool user_specified)
 	console_set_on_cmdline = 1;
 }
 
-static int __add_preferred_console(char *name, const short idx, char *options,
+static int __add_preferred_console(const char *name, const short idx, char *options,
 				   char *brl_options, bool user_specified)
 {
 	struct console_cmdline *c;
@@ -2521,7 +2521,7 @@ __setup("console=", console_setup);
  * commonly to provide a default console (ie from PROM variables) when
  * the user has not supplied one.
  */
-int add_preferred_console(char *name, const short idx, char *options)
+int add_preferred_console(const char *name, const short idx, char *options)
 {
 	return __add_preferred_console(name, idx, options, NULL, false);
 }