contexts: improve filectx eq test

mercurial/context.py

@@ -184,7 +184,7 b' class filectx(object):'
     def __eq__(self, other):
         try:
             return (self._path == other._path
-                    and self._changeid == other._changeid)
+                    and self._fileid == other._fileid)
         except AttributeError:
             return False