Claude review: drm/exec: drm_exec.h: eliminate kernel-doc warnings

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

Patch Review

**Change 1 — `Returns` → `Returns:`** (line 88 of the mbox)

```diff
- * Returns true if the drm_exec object has run into some contention while
+ * Returns: true if the drm_exec object has run into some contention while
```

Correct. The kernel-doc parser requires the `Returns:` keyword (with colon) to properly recognize and format return value descriptions. Without the colon, kernel-doc emits:
```
Warning: include/drm/drm_exec.h:146 No description found for return value of 'drm_exec_is_contended'
```

**Change 2 — `@exec` → `@_exec`** (line 97 of the mbox)

```diff
- * @exec: drm_exec object
+ * @_exec: drm_exec object
```

Correct. The `drm_exec_retry()` macro uses `_exec` as its parameter name (with leading underscore, a common pattern for macro arguments to avoid shadowing), but the kernel-doc comment documented it as `@exec`. This mismatch produces two warnings — the actual parameter `_exec` is undescribed and `exec` is flagged as excess. The fix aligns the documentation with the actual parameter name.

**No issues found.** Both changes are straightforward kernel-doc documentation fixes with no functional impact.

---
Generated by Claude Code Patch Reviewer