Fix an odd looking array

Summary: This array looks a little odd, most likely due to the autofix applied by ArcanistXHPASTLinter::LINT_ARRAY_SEPARATOR. See D12296 in which I attempt to improve the autocorrection from this linter rule.

Test Plan: N/A

Reviewers: epriestley, Blessed Reviewers

Reviewed By: epriestley, Blessed Reviewers

Subscribers: epriestley

Differential Revision: https://secure.phabricator.com/D12280