cleanup: prefer matchmod.{always,never}() over accessing matchers directly

We have these factory methods so we should use them.

Differential Revision: https://phab.mercurial-scm.org/D5927

mercurial/changegroup.py

@@ -1313,9 +1313,9 b' def getbundler(version, repo, bundlecaps'
     assert version in supportedoutgoingversions(repo)
 
     if matcher is None:
-        matcher = matchmod.alwaysmatcher(repo.root, '')
+        matcher = matchmod.always(repo.root, '')
     if oldmatcher is None:
-        oldmatcher = matchmod.nevermatcher(repo.root, '')
+        oldmatcher = matchmod.never(repo.root, '')
 
     if version == '01' and not matcher.always():
         raise error.ProgrammingError('version 01 changegroups do not support '

mercurial/fileset.py

@@ -540,8 +540,7 b' class matchctx(object):'
     def never(self):
         """Create a matcher to select nothing"""
         repo = self.ctx.repo()
-        return matchmod.nevermatcher(repo.root, repo.getcwd(),
-                                     badfn=self._badfn)
+        return matchmod.never(repo.root, repo.getcwd(), badfn=self._badfn)
 
 def match(ctx, expr, badfn=None):
     """Create a matcher for a single fileset expression"""

mercurial/subrepo.py

@@ -323,7 +323,7 b' class abstractsubrepo(object):'
 
     def matchfileset(self, expr, badfn=None):
         """Resolve the fileset expression for this repo"""
-        return matchmod.nevermatcher(self.wvfs.base, '', badfn=badfn)
+        return matchmod.never(self.wvfs.base, '', badfn=badfn)
 
     def printfiles(self, ui, m, fm, fmt, subrepos):
         """handle the files command for this subrepo"""