diff-lib: stop calling diff_setup_done() in do_diff_cache()

d44e526 (diff-lib: plug minor memory leaks in do_diff_cache(),
2020-11-14) added the call to diff_setup_done() to release the memory
of the parseopt member of struct diff_options that repo_init_revisions()
had allocated via repo_diff_setup() and prep_parse_options().

189e97b (diff: remove parseopts member from struct diff_options,
2022-12-01) did away with that allocation; diff_setup_done() doesn't
release any memory anymore.  So stop calling this function on the blank
diffopt member before it is overwritten, as this is no longer necessary.

Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Author: rscharfe

diff-lib.c

@@ -641,7 +641,6 @@ int do_diff_cache(const struct object_id *tree_oid, struct diff_options *opt)
 
 	repo_init_revisions(opt->repo, &revs, NULL);
 	copy_pathspec(&revs.prune_data, &opt->pathspec);
-	diff_setup_done(&revs.diffopt);
 	revs.diffopt = *opt;
 
 	if (diff_cache(&revs, tree_oid, NULL, 1))