tests : fix test-chat-template --no-common option (ggml-org#25075)

Author: CISC

tests/test-chat-template.cpp

@@ -135,7 +135,7 @@ int main(int argc, char ** argv) {
             output_path = args[i + 1];
             i++;
         } else if (args[i] == "--no-common") {
-            use_common = true;
+            use_common = false;
         } else if (tmpl_path.empty()) {
             tmpl_path = args[i];
         } else {