Fix Makefile installation into ETCDIR

Author: dansimau

Makefile

@@ -6,12 +6,12 @@ all:
 install: all
 
 	install -d $(ETCDIR)/config-tracker
-	install -c -m 0644 config-tracker.conf.dist $(PREFIX)/etc/config-tracker/config-tracker.conf
-	install -c -m 0644 include.conf $(PREFIX)/etc/config-tracker
-	install -c -m 0644 exclude.conf $(PREFIX)/etc/config-tracker
+	install -c -m 0644 config-tracker.conf.dist $(ETCDIR)/config-tracker/config-tracker.conf
+	install -c -m 0644 include.conf $(ETCDIR)/config-tracker
+	install -c -m 0644 exclude.conf $(ETCDIR)/config-tracker
 
 	install -d $(ETCDIR)/cron.d
-	install -c -m 0644 contrib/cron $(PREFIX)/etc/cron.d
+	install -c -m 0644 contrib/cron $(ETCDIR)/cron.d
 
 	install -d $(PREFIX)/share/config-tracker
 	install -c -m 0755 contrib/post-commit $(PREFIX)/share/config-tracker