### What this PR does / why we need it?
Fix the synchronization deadlock issue in DispathFFNCombine module that
occurs on NPU cards when the number of experts per card exceeds 16 (the
bug manifests prominently when set to 32/128).
### Does this PR introduce _any_ user-facing change?
No, this is a bug fix for internal synchronization logic specific to NPU
expert dispatch, with no impact on external APIs, interfaces, or
end-user behaviors.
- vLLM version: v0.14.1
- vLLM main:
dc917cceb8
Signed-off-by: xulei_ict <xulei292@huawei.com>
Co-authored-by: xulei_ict <xulei292@huawei.com>
77ea873224