tests: check-code all python files in one run

tests/test-check-code-hg.t

@@ -1,33 +1,31 b''
   $ check_code="$TESTDIR"/../contrib/check-code.py
   $ cd "$TESTDIR"/..
   $ if hg identify -q > /dev/null 2>&1; then :
   > else
   >     echo "skipped: not a Mercurial working dir" >&2
   >     exit 80
   > fi
 
-New errors are not allowed. Warnings are strongly discouraged.
-
-  $ hg manifest 2>/dev/null \
-  >   | xargs "$check_code" --warnings --nolineno --per-file=0 \
-  >   || false
-
-Check Python files without py extension
+Prepare check for Python files without py extension
 
   $ cp \
   >   hg \
   >   hgweb.cgi \
   >   contrib/convert-repo \
   >   contrib/dumprevlog \
   >   contrib/hgweb.fcgi \
   >   contrib/hgweb.wsgi \
   >   contrib/simplemerge \
   >   contrib/undumprevlog \
   >   i18n/hggettext \
   >   i18n/posplit \
   >   tests/hghave \
   >   tests/dummyssh \
   >   "$TESTTMP"/
   $ for f in "$TESTTMP"/*; do cp "$f" "$f.py"; done
-  $ "$check_code" --warnings --nolineno --per-file=0 "$TESTTMP"/*.py \
+
+New errors are not allowed. Warnings are strongly discouraged.
+
+  $ { hg manifest 2>/dev/null; ls "$TESTTMP"/*.py; } \
+  >   | xargs "$check_code" --warnings --nolineno --per-file=0 \
   >   || false