Bug#914724: openssn FTCBFS: make install relinks with the wrong compiler

[Helmut Grohne]

Source: openssn
Version: 1.4-2
Tags: patch upstream
User: helmutg at debian.org
Usertags: rebootstrap

openssn fails to cross build from source, because a bad makefile
dependency causes make install to relink the main binary.
dh_auto_install (unlike dh_auto_build) does not pass cross tools to
make, so this step fails. The attached patch corrects the dependency and
makes openssn cross buildable. Please consider applying it.

Helmut