contrib/editmergeps.bat

store: drop the `filefilter` argument to `_walk`

No code use it anywhere. Dropping it will help replacing the function with
something with a more precise semantic.

Differential Revision: https://phab.mercurial-scm.org/D10314

@echo off
powershell -NoProfile -ExecutionPolicy unrestricted -Command "& '%~dp0\editmergeps.ps1' %*"