vfs: use 'vfs' module directly in 'hgext.transplant'

vfs: use 'vfs' module directly in 'hgext.transplant'

Now that the 'vfs' classes moved in their own module, lets use the new module
directly. We update code iteratively to help with possible bisect needs in the
future.

--- a/hgext/transplant.py	Thu Mar 02 13:31:32 2017 +0100
+++ b/hgext/transplant.py	Thu Mar 02 13:31:39 2017 +0100
@@ -35,6 +35,7 @@
     scmutil,
     smartset,
     util,
+    vfs as vfsmod,
 )
 
 class TransplantError(error.Abort):
@@ -60,7 +61,7 @@
         self.opener = opener
 
         if not opener:
-            self.opener = scmutil.vfs(self.path)
+            self.opener = vfsmod.vfs(self.path)
         self.transplants = {}
         self.dirty = False
         self.read()
@@ -103,7 +104,7 @@
     def __init__(self, ui, repo, opts):
         self.ui = ui
         self.path = repo.join('transplant')
-        self.opener = scmutil.vfs(self.path)
+        self.opener = vfsmod.vfs(self.path)
         self.transplants = transplants(self.path, 'transplants',
                                        opener=self.opener)
         def getcommiteditor():