cmdutil: return boolean result directly in want function

mercurial/cmdutil.py

@@ -1142,9 +1142,7 b' def walkchangerevs(ui, repo, pats, chang'
         if follow and not m.files():
             ff = followfilter(onlyfirst=opts.get('follow_first'))
             def want(rev):
-                if ff.match(rev) and rev in wanted:
-                    return True
-                return False
+                return ff.match(rev) and rev in wanted
         else:
             def want(rev):
                 return rev in wanted