linux-user/main: Use list_cpus() instead of cpu_list()

This way we can get rid of the if'deffery and the XXX comment
here (it's repeated in the list_cpus() function anyway).

Signed-off-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-Id: <20230424122126.236586-1-thuth@redhat.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>

linux-user/main.c

@@ -359,10 +359,7 @@ static void handle_arg_cpu(const char *arg)
 {
     cpu_model = strdup(arg);
     if (cpu_model == NULL || is_help_option(cpu_model)) {
-        /* XXX: implement xxx_cpu_list for targets that still miss it */
-#if defined(cpu_list)
-        cpu_list();
-#endif
+        list_cpus();
         exit(EXIT_FAILURE);
     }
 }