fix linting error on OSX

[marten-seemann]

Naming is consistent with the syscall package: https://golang.org/pkg/syscall/#pkg-constants

[codecov]

Codecov Report

Merging #2813 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master    #2813   +/-   ##
=======================================
  Coverage   85.92%   85.92%           
=======================================
  Files         133      133           
  Lines       12075    12075           
=======================================
  Hits        10375    10375           
  Misses       1365     1365           
  Partials      335      335           

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