Claude review: nouveau/vmm: use kzalloc_flex

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

Patch Review

**Correctness: OK**

The original code:
```c
if (!(pgt = kzalloc(sizeof(*pgt) + (sizeof(pgt->pte[0]) * lpte), GFP_KERNEL)))
```

is replaced with:
```c
if (!(pgt = kzalloc_flex(*pgt, pte, lpte)))
```

This is correct because:

1. `struct nvkm_vmm_pt` (defined in `vmm.h:18`) has a flexible array member `union nvkm_pte_tracker pte[]` at `vmm.h:58`, and the macro's `FAM` argument is `pte` — matching correctly.
2. `kzalloc_flex` expands to `__alloc_flex(kzalloc, default_gfp(), typeof(*pgt), pte, lpte)`, which uses `struct_size_t()` internally to compute the same `sizeof(*pgt) + sizeof(pgt->pte[0]) * lpte` size.
3. `default_gfp()` with no extra arguments resolves to `GFP_KERNEL` (via `include/linux/gfp.h:18`), matching the original explicit `GFP_KERNEL`.
4. The `__alloc_flex` macro at `slab.h:990` also handles `__counted_by()` annotation tracking if present, which is a bonus.

**Minor nit on commit message:** The commit message says "Use the proper macro do to these sizeof calculations" — there's a typo: "do to" should be "to do". Very minor, but worth fixing before applying.

**Verdict:** The patch is correct and a clean mechanical conversion. Recommend applying with the typo fix in the commit message.

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Generated by Claude Code Patch Reviewer