pack-objects: simplify --filter handling
pack-objects uses OPT_PARSE_LIST_OBJECTS_FILTER_INIT() to initialize the a rev_info struct lazily before populating its filter member using the --filter option values. It tracks whether the initialization is needed using the .have_revs member of the callback data. There is a better way: Use a stand-alone list_objects_filter_options struct and build a rev_info struct with its .filter member after option parsing. This allows using the simpler OPT_PARSE_LIST_OBJECTS_FILTER() and getting rid of the extra callback mechanism. Even simpler would be using a struct rev_info as before 5cb28270a1 (pack-objects: lazily set up "struct rev_info", don't leak, 2022-03-28), but that would expose a memory leak caused by repo_init_revisions() followed by release_revisions() without a setup_revisions() call in between. Using list_objects_filter_options also allows pushing the rev_info struct into get_object_list(), where it arguably belongs. Either way, this is all left for later. Helped-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: René Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>