Update menu_cbs_ok.c

Fixed variable declaration for ISO requirement.

menu/cbs/menu_cbs_ok.c

@@ -5918,6 +5918,7 @@ static int action_ok_add_entry_to_playlist(const char *path,
 static void action_input_add_entry_to_new_playlist(void *userdata, const char *line)
 {
    settings_t *settings             = config_get_ptr();
+   size_t path_length               = 0;
    char path[PATH_MAX_LENGTH];
 
    menu_input_dialog_end();
@@ -5926,7 +5927,7 @@ static void action_input_add_entry_to_new_playlist(void *userdata, const char *l
       return;
 
    /* Create path for new file */
-   size_t path_length = fill_pathname_join_special(path, settings->paths.directory_playlist, line, sizeof(path));
+   path_length = fill_pathname_join_special(path, settings->paths.directory_playlist, line, sizeof(path));
    strlcat(path, ".lpl",  sizeof(path) - path_length);
 
    action_ok_add_entry_to_playlist(NULL, path, 0, 0, 0);