tests: stabilize test-eol-update on Windows

These appeared in the recent eol fix series.  I'm not sure about the identity
mismatch warning- it seems like a general timing issue, because it happened on
the first run but not when run with `--loop`.  The buildbot also flagged this.

Differential Revision: https://phab.mercurial-scm.org/D7112

tests/test-eol-update.t

@@ -250,6 +250,7 b' is filtered with tolf, and everything is'
   eol: detected change in .hgeol
   filtering .hgeol through isbinary
   filtering a.txt through tolf
+  skip updating dirstate: identity mismatch (?)
   $ hg diff
 
 Things were clean, and updating again will not change anything:
@@ -263,6 +264,7 b' Things were clean, and updating again wi'
    branchmerge: False, force: True, partial: False
    ancestor: 15cbdf8ca3db+, local: 15cbdf8ca3db+, remote: 15cbdf8ca3db
   calling hook preupdate.eol: hgext.eol.preupdate
+  starting 4 threads for background file closing (?)
   0 files updated, 0 files merged, 0 files removed, 0 files unresolved
 
   $ touch .hgeol *