Fix deprecation warning

[codecov[bot]]

Codecov Report

Patch coverage: 100.00% and project coverage change: +0.02 :tada:

Comparison is base (f06b776) 84.48% compared to head (0d97fc6) 84.51%.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #219 +/- ## ========================================== + Coverage 84.48% 84.51% +0.02% ========================================== Files 18 18 Lines 1921 1924 +3 ========================================== + Hits 1623 1626 +3 Misses 298 298 ``` | [Impacted Files](https://codecov.io/gh/JuliaDiff/ReverseDiff.jl/pull/219?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=JuliaDiff) | Coverage Δ | | |---|---|---| | [src/derivatives/broadcast.jl](https://codecov.io/gh/JuliaDiff/ReverseDiff.jl/pull/219?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=JuliaDiff#diff-c3JjL2Rlcml2YXRpdmVzL2Jyb2FkY2FzdC5qbA==) | `90.60% <100.00%> (ø)` | | | [src/macros.jl](https://codecov.io/gh/JuliaDiff/ReverseDiff.jl/pull/219?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=JuliaDiff#diff-c3JjL21hY3Jvcy5qbA==) | `94.17% <0.00%> (+0.08%)` | :arrow_up: | Help us with your feedback. Take ten seconds to tell us [how you rate us](https://about.codecov.io/nps?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=JuliaDiff). Have a feature suggestion? [Share it here.](https://app.codecov.io/gh/feedback/?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=JuliaDiff)

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