Fixed an entity class name.

Broken in #7940.
merged branch jakzal/benchmark-tests-fix (PR #9117)

This PR was merged into the 2.2 branch.

Discussion
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Fixed an entity class name in a benchmark test

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | -
| License       | MIT
| Doc PR        | -

Broken in #7940 (67ba1314580ad63cbbf923b59157f226210d62ce). Since benchmark tests are not run on travis, it didn't complain.

Commits
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50ff35a Fixed an entity class name.