phases: simplify revset in updatephases

(Pointed by Yuya Nishihara)

mercurial/phases.py

@@ -599,8 +599,8 b' def updatephases(repo, trgetter, headsby'
     # to update. This avoid creating empty transaction during no-op operation.
 
     for phase in allphases[:-1]:
-        revset = '%%ln - _phase(%d)' % phase
-        heads = [c.node() for c in repo.set(revset, headsbyphase[phase])]
+        revset = '%ln - _phase(%s)'
+        heads = [c.node() for c in repo.set(revset, headsbyphase[phase], phase)]
         if heads:
             advanceboundary(repo, trgetter(), phase, heads)