BLD: use inline macro
closes #13448

This built locally (on Windows) for py27 and py35.

## [Current coverage](https://codecov.io/gh/pydata/pandas/pull/13456?src=pr) is **84.28%**

> Merging [#13456](https://codecov.io/gh/pydata/pandas/pull/13456?src=pr) into [master](https://codecov.io/gh/pydata/pandas/branch/master?src=pr) will increase coverage by **<.01%**

``` diff
@@             master     #13456   diff @@
==========================================
  Files           138        138          
  Lines         50929      50929          
  Methods           0          0          
  Messages          0          0          
  Branches          0          0          
==========================================
+ Hits          42925      42926     +1   
+ Misses         8004       8003     -1   
  Partials          0          0          
```

> Powered by [Codecov](https://codecov.io?src=pr). Last updated by [f752886...22a4781](https://codecov.io/gh/pydata/pandas/compare/f7528866e07048f051f46f621ca76947730c7d32...22a478101457db70e20f8b4ee44067fff203ada8)
 thanks @chris-b1 this seems to fix.
