fix(vdec): serialize capture ownership during flush

[mingjie-wu-spacemit]

Summary

• Pause new capture dequeue requests while a channel flush is in progress.
• Wait for an in-flight dequeue to finish before flushing the capture queue.
• Serialize capture ownership updates and recycle QBUF operations without holding the ownership lock across the existing 100 ms waits.
• Drain the GetFrame depth queue and re-queue only buffers that were still decoder-owned before the flush.
• Wake paused output work during channel shutdown.

Validation

• scripts/lint/lint_cpp.sh mpi/vdec
• Clean Release CMake build

[spacemit-robot-ci]

Robot CI AI Review

• PR: fix(vdec): serialize capture ownership during flush #39 fix(vdec): serialize capture ownership during flush
• Project: components/multimedia/mpp
• Commit: 36435dfaa962

结论：发现 1 个需要处理的问题。

发现：

1. [严重] mpi/vdec/vdec.c:1494-1516 flush 失败时缓冲区所有权状态被错误清空且未恢复
   代码在调用 pChn->stOps.flush() 之前，无条件将所有 buffer 的 bInDecoder 置为 MPP_FALSE（同时记录 wasInDecoder/hadDecoderRef 用于之后重新入队）。但重新入队/恢复状态的循环被包在 if (ret == MPP_OK) 内，只有 flush 成功时才会执行。如果 pChn->stOps.flush() 返回失败，原本仍被 decoder 持有（wasInDecoder[i] == TRUE）的 buffer 会被永久标记为 bInDecoder = FALSE，但既没有真正被 dequeue，也没有被重新 queue 回 decoder，导致缓冲区所有权状态与实际不一致。后续 recycle/output 线程可能据此误判该 buffer 已可回收/复用，产生 use-after-free 或与 decoder 侧状态冲突的风险。
   建议：在 ret != MPP_OK 分支中也要处理这些 buffer，例如恢复其 bInDecoder 为原值，或者明确记录/上报错误状态，避免所有权信息与硬件/驱动实际状态脱节。

备注：worker-cache review 失败，已回退 baseline review：worker-cache review failed: snode5: busy; hp-probook: sync worker helper failed: ssh: connect to host 10.0.91.193 port 22: No route to host