avoid more build warnings on Windows

Annex/Content.hs

@@ -120,7 +120,7 @@ inAnnexSafe = inAnnex' (fromMaybe False) (Just False) go
  - it. (If the content is not present, no locking is done.) -}
 lockContent :: Key -> Annex a -> Annex a
 #ifndef mingw32_HOST_OS
-lockContent key a =
+lockContent key a = do
 	file <- calcRepo $ gitAnnexLocation key
 	bracketIO (openforlock file >>= lock) unlock (const a)
   where

Annex/Environment.hs

@@ -10,12 +10,15 @@
 module Annex.Environment where
 
 import Common.Annex
-import Utility.Env
 import Utility.UserInfo
 import qualified Git.Config
 import Config
 import Annex.Exception
 
+#ifndef mingw32_HOST_OS
+import Utility.Env
+#endif
+
 {- Checks that the system's environment allows git to function.
  - Git requires a GECOS username, or suitable git configuration, or
  - environment variables.

Annex/Journal.hs

@@ -86,12 +86,13 @@ lockJournal a = do
 	mode <- annexFileMode
 	bracketIO (lock lockfile mode) unlock (const a)
   where
-	lock lockfile mode = do
 #ifndef mingw32_HOST_OS
+	lock lockfile mode = do
 		l <- noUmask mode $ createFile lockfile mode
 		waitToSetLock l (WriteLock, AbsoluteSeek, 0, 0)
 		return l
 #else
+	lock lockfile _mode = do
 		writeFile lockfile ""
 		return lockfile
 #endif