largefiles: remove confusing 'or None' from predicate

The match function that is overriden returns a boolean value, so
adding 'or None' is both unnecessary and confusing.

hgext/largefiles/overrides.py

@@ -35,7 +35,7 b' def installnormalfilesmatchfn(manifest):'
         m._fmap = set(m._files)
         m._always = False
         origmatchfn = m.matchfn
-        m.matchfn = lambda f: notlfile(f) and origmatchfn(f) or None
+        m.matchfn = lambda f: notlfile(f) and origmatchfn(f)
         return m
     oldmatch = installmatchfn(overridematch)