Substitute repoze.lru for backports.functools_lru_cache as we already
have repoze.lru in Userland/Solaris and backports.functools_lru_cache
has some 4th party dependencies.

This change will not be sent upstream.

--- pylint-1.6.4/pylint/checkers/variables.py.orig	2016-09-29 16:26:46.454143452 +0000
+++ pylint-1.6.4/pylint/checkers/variables.py	2016-09-29 16:29:51.776301211 +0000
@@ -13,7 +13,7 @@
 try:
     from functools import lru_cache
 except ImportError:
-    from backports.functools_lru_cache import lru_cache
+    from repoze.lru import lru_cache
 
 import six