Fix VLLM_ASCEND_LLMDD_RPC_PORT renaming

[wyu0-0]

What this PR does / why we need it?

This PR implements the renaming of the environment variable VLLM_LLMDD_RPC_PORT to VLLM_ASCEND_LLMDD_RPC_PORT, as proposed and tracked in #2450. The renaming is intended to align the variable naming convention with other Ascend-specific environment variables in the vllm-ascend codebase, enhancing consistency and clarity for developers and users working with Ascend-based deployments.

Does this PR introduce any user-facing change?

NA

How was this patch tested?

CI passed with existing test.

• vLLM version: v0.10.2
• vLLM main: vllm-project/vllm@9607d5e

[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 correctly renames the environment variable VLLM_LLMDD_RPC_PORT to VLLM_ASCEND_LLMDD_RPC_PORT in an example and a test script, which aligns with the goal of improving naming consistency. While the renaming is correct, I've pointed out a high-severity maintainability issue in tests/e2e/pd_disaggreate/run_edge_case_test.sh. The script redefines the BASE_CMD variable, which is an error-prone practice. I've recommended using unique variable names for the prefill and decode commands to make the script more robust and easier to maintain.

[gemini-code-assist]

The variable BASE_CMD is defined here and then redefined on line 93 for the decode instance. This pattern of reusing and redefining variables is error-prone and can make the script difficult to maintain. To improve clarity and prevent potential bugs, I recommend using a unique name for this command, such as PREFILL_BASE_CMD.

[gemini-code-assist]

This line redefines the BASE_CMD variable, which was first assigned on line 73. Reusing variable names this way can lead to confusion and makes the script fragile. A better practice is to use a distinct variable name for the decode command, like DECODE_BASE_CMD, to make the script's logic clearer and more robust against future changes.