[Minor] clean up multimodal processor and tokenizer manager (#7624)

python/sglang/srt/managers/io_struct.py

@@ -22,17 +22,16 @@ from dataclasses import dataclass, field
 from enum import Enum
 from typing import TYPE_CHECKING, Any, Dict, List, Optional, Set, Union
 
+from sglang.srt.managers.schedule_batch import BaseFinishReason
 from sglang.srt.multimodal.mm_utils import has_valid_data
+from sglang.srt.sampling.sampling_params import SamplingParams
 
-# handle serialization of Image for pydantic
+# Handle serialization of Image for pydantic
 if TYPE_CHECKING:
     from PIL.Image import Image
 else:
     Image = Any
 
-from sglang.srt.managers.schedule_batch import BaseFinishReason
-from sglang.srt.sampling.sampling_params import SamplingParams
-
 
 @dataclass
 class SessionParams:
@@ -182,6 +181,7 @@ class GenerateReqInput:
         # Determine parallel sample count
         if self.sampling_params is None:
             self.parallel_sample_num = 1
+            return
         elif isinstance(self.sampling_params, dict):
             self.parallel_sample_num = self.sampling_params.get("n", 1)
         else:  # isinstance(self.sampling_params, list):