Sped up query commands that read the git-annex branch by around 5%

The only price paid is one additional MVar read per write to the journal.
Presumably writing a journal file dominiates over a MVar read time by
several orders of magnitude.

--batch does not get the speedup because then it needs to notice when
another process has made a change. Also made the assistant and other damon
modes bypass the optimisation, which would not help them anyway.

CmdLine/Batch.hs

@@ -14,6 +14,7 @@ import CmdLine.GitAnnex.Options
 import Options.Applicative
 import Limit
 import Types.FileMatcher
+import Annex.BranchState
 
 data BatchMode = Batch BatchFormat | NoBatch
 
@@ -72,7 +73,9 @@ batchInput fmt parser a = go =<< batchLines fmt
 	parseerr s = giveup $ "Batch input parse failure: " ++ s
 
 batchLines :: BatchFormat -> Annex [String]
-batchLines fmt = liftIO $ splitter <$> getContents
+batchLines fmt = do
+	enableInteractiveJournalAccess
+	liftIO $ splitter <$> getContents
   where
 	splitter = case fmt of
 		BatchLine -> lines