$NetBSD$

Install to prefix.

--- files/Makefile.in.orig	2018-05-16 17:41:09.000000000 +0000
+++ files/Makefile.in
@@ -7,7 +7,7 @@ distclean:
 maintainer-clean:
 
 install:
-	find . -mindepth 1 -maxdepth 1 -type d -exec cp -R {} $(DESTDIR)/ \;
+	cd usr && find . -mindepth 1 -maxdepth 1 -type d -exec cp -R {} $(DESTDIR)$(PREFIX)/ \;
 
 uninstall:
-	find . -mindepth 1 -type f -exec rm $(DESTDIR)/{} \;
+	find . -mindepth 1 -type f -exec rm $(DESTDIR)$(PREFIX)/{} \;