Claude review: drm/vc4: Fix a memory leak in hang state error path

[Claude Code Review Bot <claude-review@example.com>]

Patch Review

**Verdict: Good fix.**

Two early returns in `vc4_save_hang_state()` leaked the `kernel_state` allocation. The patch consolidates them into a single `err_free_state` label that unlocks the spinlock and frees `kernel_state`.

```c
-if (!exec[0] && !exec[1]) {
-    spin_unlock_irqrestore(&vc4->job_lock, irqflags);
-    return;
-}
+if (!exec[0] && !exec[1])
+    goto err_free_state;
```

And:
```c
+err_free_state:
+    spin_unlock_irqrestore(&vc4->job_lock, irqflags);
+    kfree(kernel_state);
```

Both error paths hold the spinlock, and the label correctly releases it before freeing. Note this patch depends on patch 2 being applied first (the `kfree(state->bo)` in `vc4_free_hang_state`), but the second early return (`!kernel_state->bo`) happens before `bo` is allocated, so `kfree(kernel_state)` alone is sufficient at the error label — `kernel_state->bo` is NULL in both error cases (either never assigned, or the allocation failed). Correct.

No issues.

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Generated by Claude Code Patch Reviewer