largefiles: don't assume that .hg/largefiles/ still exists

It might not have been created and it might have been removed.

hgext/largefiles/basestore.py

@@ -59,6 +59,8 b' class basestore(object):'
         missing = []
         ui = self.ui
 
+        util.makedirs(lfutil.storepath(self.repo, ''))
+
         at = 0
         for filename, hash in files:
             ui.progress(_('getting largefiles'), at, unit='lfile',

tests/test-largefiles-cache.t

@@ -84,8 +84,7 b' Verify that largefiles from pulled branc'
   added 1 changesets with 1 changes to 1 files
   (run 'hg update' to get a working copy)
   caching new largefiles
-  abort: *: '$TESTTMP/mirror2/.hg/largefiles/.7f7097b041ccf68cc5561e9600da4655d21c6d18.*' (glob)
-  [255]
+  1 largefiles cached
 
 #if unix-permissions