fix EAGLE 2 non greedy case

[zhyncs]

Motivation

Modifications

Checklist

• Format your code according to the Code Formatting with Pre-Commit.
• Add unit tests as outlined in the Running Unit Tests.
• Update documentation / docstrings / example tutorials as needed, according to Writing Documentation.
• Provide throughput / latency benchmark results and accuracy evaluation results as needed, according to Benchmark and Profiling and Accuracy Results.
• For reviewers: If you haven't made any contributions to this PR and are only assisting with merging the main branch, please remove yourself as a co-author when merging the PR.

[zhyncs]

All EAGLE 2-related CIs have passed, and these are the other local test commands.

python3 -m sglang.launch_server --model meta-llama/Llama-2-7b-chat-hf

python3 -m sglang.launch_server --model meta-llama/Llama-2-7b-chat-hf  --speculative-algo EAGLE --speculative-draft lmzheng/sglang-EAGLE-llama2-chat-7B --speculative-num-steps 5 --speculative-eagle-topk 8 --speculative-num-draft-tokens 64 --mem-fraction 0.7

for i in {1..2}; do
  curl -s -X POST http://localhost:30000/v1/chat/completions \
    -H "Content-Type: application/json" \
    -d '{
      "model": "test",
      "messages": [
        {"role": "system", "content": "You know mathematics."},
        {"role": "user", "content": "What is 1 + 1? Answer with just the number as the only word. Do not put whitespace in front."}
      ],
      "temperature": 0,
      "max_tokens": 32
  }' | jq '.choices[0].message.content'
done

for i in {1..2}; do
  curl -s -X POST http://localhost:30000/v1/chat/completions \
    -H "Content-Type: application/json" \
    -d '{
      "model": "test",
      "messages": [
        {"role": "system", "content": "You know mathematics."},
        {"role": "user", "content": "What is 1 + 1? Answer with just the number as the only word. Do not put whitespace in front."}
      ],
      "temperature": 0.6,
      "max_tokens": 32
  }' | jq '.choices[0].message.content'
done

[zhyncs]

TODOs
#3395 @zhyncs
#3409 @Ying1123