walkchangerevs: simplify by using match.always() method
Since "slowpath = match.anypats() or (match.files() and
opts.get('removed'))", we can simplify the condition "not slowpath and
not match.files()" to "not match.anypats() and not match.files()",
which is equivalent to "match.always()".
--- a/mercurial/cmdutil.py Tue Oct 28 22:43:59 2014 -0700
+++ b/mercurial/cmdutil.py Tue Oct 28 22:32:18 2014 -0700
@@ -1698,7 +1698,7 @@
# wanted: a cache of filenames that were changed (ctx.files()) and that
# match the file filtering conditions.
- if not slowpath and not match.files():
+ if match.always():
# No files, no patterns. Display all revs.
wanted = revs