Merge request: wrong changes count

Summary

Merge request: changes tab shows wrong number

Steps to reproduce

Create a merge request with 100+ changed files

Expected behavior

I would expect the number to be correct: so for my "Actual behavior" screenshot, I would expect a tab like this: [Changes (120)]

Actual behavior

It can also bee seen in this merge request: https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/8903/diffs