Fix lint in examples/offline_embed.py (#1618)

### What this PR does / why we need it?
Fix lint

### Does this PR introduce _any_ user-facing change?
No

### How was this patch tested?
CI passed

Signed-off-by: Yikun Jiang <yikunkero@gmail.com>

Author: Yikun

examples/offline_embed.py

@@ -18,11 +18,13 @@
 #
 
 import os
+
 os.environ["VLLM_USE_MODELSCOPE"] = "True"
 
 import torch
 from vllm import LLM
 
+
 def get_detailed_instruct(task_description: str, query: str) -> str:
     return f'Instruct: {task_description}\nQuery:{query}'