options: use M_OPT_EXIT with -V

Otherwise, output will actually be muted during pre-pase stage, and it
will exit before running it again with output enabled.

options/options.c

@@ -68,7 +68,7 @@ static int print_version_opt(const m_option_t *opt, const char *name,
                              const char *param)
 {
     mp_print_version(true);
-    exit(0);
+    return M_OPT_EXIT;
 }
 
 #if HAVE_RADIO