Fix missing import.

--HG--
branch : setuptools
extra : convert_revision : svn%3A6015fed2-1504-0410-9fe1-9d1591cc4771/sandbox/trunk/setuptools%4042195

setuptools/command/easy_install.py

@@ -889,6 +889,7 @@ See the setuptools documentation for the "develop" command for more info.
 
     def _expand(self, *attrs):
         config_vars = self.get_finalized_command('install').config_vars
+        from distutils.util import subst_vars
         for attr in attrs:
             val = getattr(self, attr)
             if val is not None:
@@ -899,7 +900,6 @@ See the setuptools documentation for the "develop" command for more info.
 
 
 
-
 def get_site_dirs():
     # return a list of 'site' dirs, based on 'site' module's code to do this
     sitedirs = []