Fixes unused buflen in gen_matrix_entry

[bhess]

Summary:
Fixes unused buflen variable in gen_matrix_entry. Detected when importing the code to liboqs and running a build with scan_build.

Performed local tests:

• lint passing (not sure how to run this locally.)
• tests all passing
• tests bench passing
• tests cbmc passing (I might be missing some dependencies to run this.)

Do you expect this change to impact performance: No

If yes, please provide local benchmarking results.

[hanno-becker]

LGTM!

[hanno-becker]

tests cbmc passing (I might be missing some dependencies to run this.)

@bhess The easiest way (and indeed really easy) is to use nix (setting the CBMC toolchain up yourself isn't much fun). Have you tried? See https://github.com/pq-code-package/mlkem-native/blob/main/BUILDING.md#nix-setup

lint passing (not sure how to run this locally.)

Assuming you installed nix and entered the shell with nix develop --experimental-features 'nix-command flakes' (which for the first time only will take you maybe ~10min, henceforth seconds), it should just be lint

[hanno-becker]

Full CI passed.

[bhess]

tests cbmc passing (I might be missing some dependencies to run this.)

@bhess The easiest way (and indeed really easy) is to use nix (setting the CBMC toolchain up yourself isn't much fun). Have you tried? See https://github.com/pq-code-package/mlkem-native/blob/main/BUILDING.md#nix-setup

lint passing (not sure how to run this locally.)

Assuming you installed nix and entered the shell with nix develop --experimental-features 'nix-command flakes' (which for the first time only will take you maybe ~10min, henceforth seconds), it should just be lint

Thanks for the hint using nix! I'll give it a try.