tests/check-gendoc

patch: move yielding "\n" to the end of loop

The original logic makes it harder to reason about - it yields the "\n"
character belonging to the last line in the next loop iteration.

The new code is in theory a little bit slower. But is more readable. It
makes the following changes easier to read.

Differential Revision: https://phab.mercurial-scm.org/D3210

#!/bin/sh
HGENCODING=UTF-8
export HGENCODING

echo ".. -*- coding: utf-8 -*-" > gendoc.txt
echo "" >> gendoc.txt
LANGUAGE=$1 python "$TESTDIR/../doc/gendoc.py" >> gendoc.txt 2> /dev/null || exit

echo "checking for parse errors"
python "$TESTDIR/../doc/docchecker" gendoc.txt
python "$TESTDIR/../doc/runrst" html gendoc.txt /dev/null