Use a local name (it was intended to be used but overlooked).

This was caught in the distutils2 repo by pyflakes.
diff --git a/Lib/pkgutil.py b/Lib/pkgutil.py
index 2dd20cd..c561c13 100644
--- a/Lib/pkgutil.py
+++ b/Lib/pkgutil.py
@@ -307,9 +307,9 @@
     def get_filename(self, fullname=None):
         fullname = self._fix_name(fullname)
         mod_type = self.etc[2]
-        if self.etc[2]==imp.PKG_DIRECTORY:
+        if mod_type==imp.PKG_DIRECTORY:
             return self._get_delegate().get_filename()
-        elif self.etc[2] in (imp.PY_SOURCE, imp.PY_COMPILED, imp.C_EXTENSION):
+        elif mod_type in (imp.PY_SOURCE, imp.PY_COMPILED, imp.C_EXTENSION):
             return self.filename
         return None