Claude review: drm/exec, drm/xe, drm/amdgpu: Add an accessor for struct drm_exec::ticket

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

Patch Review

**Assessment: Good.**

The accessor is trivially correct:

```c
static inline struct ww_acquire_ctx *drm_exec_ticket(struct drm_exec *exec)
{
	return &exec->ticket;
}
```

All driver-side conversions are mechanical and correct. The internal uses in `drm_exec.c` (`drm_exec_cleanup`, `drm_exec_fini`, `drm_exec_lock_contended`) are deliberately not converted, which is appropriate since those are the implementation of drm_exec itself and would not need to change when subclassing.

One observation about the amdgpu `dma_resv_locking_ctx` comparison:

```c
-	if (dma_resv_locking_ctx((*bo)->tbo.base.resv) != &parser->exec.ticket)
+	if (dma_resv_locking_ctx((*bo)->tbo.base.resv) != drm_exec_ticket(&parser->exec))
```

This pointer comparison remains correct since `drm_exec_ticket` returns `&exec->ticket`, which is the same address.

Minor style note: the kdoc says `drm_exec_ticket` without the `()` convention used elsewhere for function names, but this is consistent with many kernel kdoc examples and not an issue.

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Generated by Claude Code Patch Reviewer