perf test: Use 3 digits for test numbering now we can have more tests

perf test: Use 3 digits for test numbering now we can have more tests

This is in preparation for adding more tests that will need the test
number to be 3 digts so they align nicely in the output.

Reviewed-by: Leo Yan <leo.yan@linaro.org>
Signed-off-by: Carsten Haitzler <carsten.haitzler@arm.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Suzuki Poulouse <suzuki.poulose@arm.com>
Cc: coresight@lists.linaro.org
Link: http://lore.kernel.org/lkml/20211215160403.69264-3-carsten.haitzler@foss.arm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>