test-bloom: stop setting up Git directory twice
We're setting up the Git directory twice in the `test-tool bloom`
helper, once at the beginning of `cmd_bloom()` and once in the local
subcommand implementation `get_bloom_filter_for_commit()`. This can lead
to memory leaks as we'll overwrite variables of `the_repository` with
newly allocated data structures. On top of that it's simply unnecessary.
Fix this by only setting up the Git directory once.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>