[Fix][Fish Speech] Remove redundant get_vocab() in control token encoding (#2842)

Signed-off-by: Sy03 <1370724210@qq.com>

vllm_omni/model_executor/models/fish_speech/prompt_utils.py

@@ -38,10 +38,7 @@ def _encode_plain_text(tokenizer: Any, text: str) -> list[int]:
 
 
 def _encode_control_token(tokenizer: Any, token: str) -> list[int]:
-    vocab = tokenizer.get_vocab() if hasattr(tokenizer, "get_vocab") else {}
-    token_id = vocab.get(token)
-    if token_id is None:
-        token_id = tokenizer.convert_tokens_to_ids(token)
+    token_id = tokenizer.convert_tokens_to_ids(token)
     if token_id is None or token_id == getattr(tokenizer, "unk_token_id", None):
         raise ValueError(f"Fish Speech tokenizer is missing required control token: {token}")
     return [int(token_id)]