Remove redundant row_indices unsqueeze operation in MiniCPMO (vllm-project#22528)

Signed-off-by: zitian.zhao <[email protected]>
Signed-off-by: jingyu <[email protected]>

Author: skyloevil

vllm/model_executor/models/minicpmo.py

@@ -605,7 +605,6 @@ def subsequent_chunk_mask(
                                   max=size)
         # Create column indices for broadcasting
         col_indices = torch.arange(size, device=device).unsqueeze(0)
-        row_indices = row_indices.unsqueeze(1)
         start_indices = start_indices.unsqueeze(1)
         end_indices = end_indices.unsqueeze(1)
         # Vectorized mask creation