[Doc] eval-type not support service but server, and test the result b…

[L4-1024]

…y online inference

What this PR does / why we need it?

Does this PR introduce any user-facing change?

How was this patch tested?

• vLLM version: v0.10.2
• vLLM main: vllm-project/vllm@fec347d

[github-actions]

👋 Hi! Thank you for contributing to the vLLM Ascend project. The following points will speed up your PR merge:‌‌

• A PR should do only one thing, smaller PRs enable faster reviews.
• Every PR should include unit tests and end-to-end tests ‌to ensure it works and is not broken by other future PRs.
• Write the commit message by fulfilling the PR description to help reviewer and future developers understand.

If CI fails, you can run linting and testing checks locally according Contributing and Testing.

[gemini-code-assist]

Code Review

This pull request provides a documentation fix for using_evalscope.md. It corrects the value for the --eval-type argument in an example command from service to server. This is a helpful change that ensures the example is accurate and executable for users, preventing potential confusion and errors. The change is correct and improves the quality of the documentation.