### What this PR does / why we need it?
Avoid failing `ci_log_summary.py` when the e2e log file is missing or
empty.
Test in CI
:https://github.com/vllm-project/vllm-ascend/actions/runs/23428406256/job/68149271871
### Does this PR introduce _any_ user-facing change?
### How was this patch tested?
- vLLM version: v0.18.0
- vLLM main:
8b6325758c
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Signed-off-by: Meihan-chen <jcccx.cmh@gmail.com>