Typecast covers entire expression to fix format warning.

- Fixes (#12636).
- changes all the typecasts to _unsinged long long_ to
  have the format specifiers work.

Reviewers: austin, bgamari, erikd, simonmar, Phyx

Reviewed By: erikd, Phyx

Subscribers: thomie

Differential Revision: https://phabricator.haskell.org/D3129