Claude review: drm/imagination: simplify pvr_fw_trace_seq_data

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

Patch Review

**Summary:** Moves the `u32 *buffer` pointer in `struct pvr_fw_trace_seq_data` to a `u32 buffer[]` flexible array member, then replaces the separate `kzalloc_obj` + `kcalloc` pair with a single `kzalloc_flex` call.

**Correctness:**

- The FAM `u32 buffer[]` is correctly placed as the last member of the struct — this is required by C for flexible array members. ✅
- `kzalloc_flex(*trace_seq_data, buffer, ROGUE_FW_TRACE_BUF_DEFAULT_SIZE_IN_DWORDS)` correctly omits the GFP flag, which defaults to `GFP_KERNEL` via the `default_gfp()` macro — matching the original `kcalloc(..., GFP_KERNEL)`. ✅
- The `kzalloc` variant zeros the memory, matching the original `kcalloc` behavior. ✅
- The removal of `kfree(trace_seq_data->buffer)` in both the error path (`err_free_buffer` label) and `fw_trace_release()` is correct since the buffer is now part of the struct allocation. ✅
- The error path cleanup is simplified from two labels (`err_free_buffer` → `err_free_data`) to one (`err_free_data`), which correctly just frees the single allocation. ✅

**All existing accesses to `trace_seq_data->buffer[idx]`** (e.g., in `read_fw_trace()` at line 276) continue to work identically — array subscript on a flexible array member works the same as on a pointer.

**Minor observations:**

- The comment was updated from `"Pointer to copy of trace data"` to `"Copy of trace data"` — appropriate since it's no longer a pointer. ✅
- The patch correctly uses `kzalloc_flex` which is the kernel's preferred macro for allocating structs with flexible array members, consistent with other callers in the tree.

**No issues found.** This is a clean, correct simplification.

Reviewed-by: AI Review <ai@review>

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Generated by Claude Code Patch Reviewer