tests/test-gendoc-pt_BR.t

tests: suppress "Checked out 1 paths of <hash>" from modern git

test-convert-git.t is failiing since git commit 0f086e6dca (checkout:
print something when checking out paths, 2018-11-13). Suppress the new
output by disambiguating the arguments with a "--" separator.

Differential Revision: https://phab.mercurial-scm.org/D5625

#require docutils gettext

  $ $TESTDIR/check-gendoc pt_BR
  checking for parse errors