printk: export symbols for debug modules

the module is out-of-tree, it saves kernel logs when panic
Signed-off-by: Enlin Mu <enlin.mu@unisoc.com>
Acked-by: Petr Mladek <pmladek@suse.com>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20230815020711.2604939-1-yunlong.xing@unisoc.com

kernel/printk/printk.c

@@ -536,12 +536,14 @@ char *log_buf_addr_get(void)
 {
 	return log_buf;
 }
+EXPORT_SYMBOL_GPL(log_buf_addr_get);
 
 /* Return log buffer size */
 u32 log_buf_len_get(void)
 {
 	return log_buf_len;
 }
+EXPORT_SYMBOL_GPL(log_buf_len_get);
 
 /*
  * Define how much of the log buffer we could take at maximum. The value