revert: drop `lexist` check in the backup logic

We are no longer trying to backup files that do not exist on disk. This check
can be safely dropped.

mercurial/cmdutil.py

@@ -2576,8 +2576,7 b' def revert(ui, repo, ctx, parents, *pats'
                     continue
                 if xlist is not None:
                     xlist.append(abs)
-                    if (dobackup and os.path.lexists(target)
-                        and wctx[abs].cmp(ctx[abs])):
+                    if (dobackup and wctx[abs].cmp(ctx[abs])):
                         bakname = "%s.orig" % rel
                         ui.note(_('saving current version of %s as %s\n') %
                                 (rel, bakname))