scmutil: respect ui.relative-paths in default match.badfn

We should probably be passing in a uipathfn here instead, so the
caller can get consistent output (between match.badfn and whatever
else it prints). I think we should ideally remove the badfn from the
matcher completely, but that's a different story. This patch is at
least not making it worse.

Differential Revision: https://phab.mercurial-scm.org/D5916

mercurial/scmutil.py

@@ -802,8 +802,9 b' def matchandpats(ctx, pats=(), opts=None'
     if not globbed and default == 'relpath':
         pats = expandpats(pats or [])
 
+    uipathfn = getuipathfn(ctx.repo(), legacyrelativevalue=True)
     def bad(f, msg):
-        ctx.repo().ui.warn("%s: %s\n" % (m.rel(f), msg))
+        ctx.repo().ui.warn("%s: %s\n" % (uipathfn(f), msg))
 
     if badfn is None:
         badfn = bad