test-check-commit: don't run hg per commit

We aren't stress testing CPU.

  $ time ./run-tests.py -l test-check-commit.t --timeout 600
  (orig) 162.59s user 17.98s system 101% cpu 2:58.55 total
  (new)  5.85s user 0.99s system 98% cpu 6.939 total

tests/test-check-commit.t

@@ -8,15 +8,16 b' Go back in the hg repo'
 
   $ cd $TESTDIR/..
 
-  $ for node in `testrepohg log --rev 'not public() and ::. and not desc("# no-check-commit")' --template '{node|short}\n'`; do
-  >    testrepohg export --git $node \
-  >        | contrib/check-commit > ${TESTTMP}/check-commit.out
+  $ mkdir "$TESTTMP/p"
+  $ testrepohg export --git -o "$TESTTMP/p/%n-%h" \
+  > -r 'not public() and ::. and not desc("# no-check-commit")'
+  $ for f in `ls "$TESTTMP/p"`; do
+  >    contrib/check-commit < "$TESTTMP/p/$f" > "$TESTTMP/check-commit.out"
   >    if [ $? -ne 0 ]; then
+  >        node="${f##*-}"
   >        echo "Revision $node does not comply with rules"
   >        echo '------------------------------------------------------'
   >        cat ${TESTTMP}/check-commit.out
   >        echo
   >   fi
   > done
-
-