incomplete parametrization / hardcoded values

[maciejskorski]

For instance, here we use the constant 15 in place of len as intended.

https://github.com/z-prize/2022-entries/blob/6afb9044028ba09cc6f2ce28221ee5df55ce7190/open-division/prize1-msm/prize1a-msm-gpu/storswiftlabs/src/util.rs#L15