Log message:
Pullup ticket #5605 - requested by sevan
devel/flex: Linux build fix

Revisions pulled up:
- devel/flex/Makefile                                           1.61

---
   Module Name:    pkgsrc
   Committed By:   triaxx
   Date:           Fri Oct 20 06:22:24 UTC 2017

   Modified Files:
           pkgsrc/devel/flex: Makefile

   Log message:
   Add workaround for fixing build on Linux

   See https://github.com/westes/flex/issues/241
   The problem is fixed in master branch and the workaround could be removed
   in the next version update.