[PATCH 0 of 2 STABLE] fix failure of test-check-code-hg.t on windows

[Simon Heimberg]

Resending the patch fixing test-check-code-hg.t failure on windows, because the failure 
moved into stable now.

[Patch 1] Can be left out if desired
It is inspired by the failure. Without this, check-code aborts when a file is not found.

[Patch 2] It fixes the failure on windows (failing since 96fd9af75834).
The problem is that xargs is earing up the \.
See failure of test-check-code-hg.t in http://hgbuildbot.kublai.com/builders/Windows%202008%20R2%20hg%20tests%20%28stable%29/builds/295/steps/run-tests.py%20%28python2.6%29/logs/stdio