bsdSetupHook: Do not define empty DESTDIR

This breaks OpenBSD, and isn't actually needed for the others after all.

Author: Ericson2314

pkgs/os-specific/bsd/setup-hook.sh

@@ -28,7 +28,6 @@ addMakeFlags() {
 
   # Definitions passed to share/mk/*.mk. Should be pretty simple -
   # eventually maybe move it to a configure script.
-  export DESTDIR=
   export USETOOLS=never
   export NOCLANGERROR=yes
   export NOGCCERROR=yes