[Bugfix] Print text alongside audio in multimodal chat example (#8130)

Signed-off-by: Gao Han <hgaoaf@connect.ust.hk>

examples/online_serving/openai_chat_completion_client_for_multimodal_generation.py

@@ -1,3 +1,6 @@
+# SPDX-License-Identifier: Apache-2.0
+# SPDX-FileCopyrightText: Copyright contributors to the vLLM-Omni project
+
 import base64
 import concurrent.futures
 import os
@@ -457,7 +460,8 @@ def run_multimodal_generation(args, client: OpenAI) -> None:
                         f.write(audio_data)
                     print(f"Audio saved to {audio_file_path}")
                     count += 1
-                elif choice.message.content:
+                # A choice can contain both audio and text.
+                if choice.message.content:
                     print("Chat completion output from text:", choice.message.content)
     else:
         printed_content = False