Factor out repeated code.
Factor out repeated code.

Tested by: none
(I just eyeballed the two code sections; this may not compile)

* contrib/server-side/fsfsfixer/fixer/fix-rev.py
  (fix_one_error): Factor out two identical chunks into..
  (grab_stderr): ..this new function.

jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion