fetch-pack: free object filter before exiting

Our fetch_pack_args holds a filter_options struct that may be populated
with allocated strings by the by the "--filter" command-line option. We
must free it before exiting to avoid a leak when the program exits.

The usual fetch code paths that use transport.c don't have the same
leak, because we do the cleanup in disconnect_git().

Fixing this leak lets us mark t5500 as leak-free.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/fetch-pack.c

@@ -293,5 +293,6 @@ int cmd_fetch_pack(int argc,
 	free(sought);
 	free_refs(fetched_refs);
 	free_refs(remote_refs);
+	list_objects_filter_release(&args.filter_options);
 	return ret;
 }

t/t5500-fetch-pack.sh

@@ -8,6 +8,7 @@ test_description='Testing multi_ack pack fetching'
 GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main
 export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
 
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 # Test fetch-pack/upload-pack pair.