Fix syntax error

[ehennestad]

Motivation

Fix syntax error. Can cause problems when compiling code (i.e #564 ) or packaging to MATLAB toolbox (mltbx file).

How to test the behavior?

N/A

Checklist

• [x] Have you ensured the PR description clearly describes the problem and solutions?
• [x] Have you checked to ensure that there aren't other open or previously closed Pull Requests for the same change?
• [x] If this PR fixes an issue, is the first line of the PR description fix #XX where XX is the issue number?

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 90.63%. Comparing base (bc4b87d) to head (4a2133b). Report is 3 commits behind head on master.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #609 +/- ## ======================================= Coverage 90.63% 90.63% ======================================= Files 106 106 Lines 4686 4686 ======================================= Hits 4247 4247 Misses 439 439 ``` | [Flag](https://app.codecov.io/gh/NeurodataWithoutBorders/matnwb/pull/609/flags?src=pr&el=flags&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=NeurodataWithoutBorders) | Coverage Δ | | |---|---|---| | [](https://app.codecov.io/gh/NeurodataWithoutBorders/matnwb/pull/609/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=NeurodataWithoutBorders) | `?` | | Flags with carried forward coverage won't be shown. [Click here](https://docs.codecov.io/docs/carryforward-flags?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=NeurodataWithoutBorders#carryforward-flags-in-the-pull-request-comment) to find out more.

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