repair: use `is_manifestlog` to recognise manifest revlog

This is simpler that comparing flag, and we want to remove these flags anyway.

mercurial/repair.py

@@ -24,7 +24,6 b' from . import ('
     phases,
     requirements,
     scmutil,
-    store,
     transaction,
     util,
 )
@@ -446,9 +445,7 b' def manifestrevlogs(repo):'
         # This logic is safe if treemanifest isn't enabled, but also
         # pointless, so we skip it if treemanifest isn't enabled.
         for entry in repo.store.data_entries():
-            if not entry.is_revlog:
-                continue
-            if entry.revlog_type == store.FILEFLAGS_MANIFESTLOG:
+            if entry.is_revlog and entry.is_manifestlog:
                 yield repo.manifestlog.getstorage(entry.target_id)