Using "1~5" isn't portable. Nobody seems to have noticed, since perhaps
people don't tend to run the perf suite on more exotic platforms. Still,
it's better to set a good example.
We can use:
perl -ne 'print if $. % 5 == 1'
instead. But we can further observe that perl does a good job of the
other parts of this pipeline, and fold the whole thing together.
Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>