Claude review: drm: fix dead default for DRM_TTM_KUNIT_TEST

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

Patch Review

**Commit message:** Clear and well-written. Explains the problem (shadowed default), the tool that found it (kconfirm), and what the fix does.

**Code change:** Correct. Looking at the existing file (`Kconfig.debug:86-94`), we can see:

```
config DRM_TTM_KUNIT_TEST
	tristate "KUnit tests for TTM" if !KUNIT_ALL_TESTS
	default n                      <-- first default, always wins
	depends on DRM && KUNIT && MMU && (UML || COMPILE_TEST)
	select DRM_TTM
	select DRM_BUDDY
	select DRM_EXPORT_FOR_TESTS if m
	select DRM_KUNIT_TEST_HELPERS
	default KUNIT_ALL_TESTS        <-- dead code, never reached
```

Removing `default n` makes `default KUNIT_ALL_TESTS` the sole default, which is the intended behavior. This is consistent with the pattern used by `DRM_SCHED_KUNIT_TEST` (line 103-107) and `DRM_KUNIT_TEST` earlier in the same file, which don't have a `default n` overriding their `default KUNIT_ALL_TESTS`.

**Minor style note:** After removal, the `default KUNIT_ALL_TESTS` on line 94 sits after several `select` statements. It would be slightly more conventional to place `default` right after `depends on` (matching `DRM_SCHED_KUNIT_TEST`'s ordering), but that's a purely cosmetic nit and not worth blocking the patch.

**Reviewed-by worthy:** Yes, this is a clean, correct fix.

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Generated by Claude Code Patch Reviewer