match: fix bug in match.visitdir()

There was a bug in my recent change to visitdir (8545bd381504) due to
the stored generator being iterated over twice. Making the generator into a
list at the start fixes this.

mercurial/match.py

@@ -197,7 +197,7 b' class match(object):'
         parentdirs = None
         if (self._includeroots and dir not in self._includeroots and
                 dir not in self._includedirs):
-            parentdirs = util.finddirs(dir)
+            parentdirs = list(util.finddirs(dir))
             if not any(parent in self._includeroots for parent in parentdirs):
                 return False
         return (not self._fileroots or '.' in self._fileroots or