pack-objects: use rev.filter when possible

In builtin/pack-objects.c, we use a 'filter_options' global to populate
the --filter=<X> argument. The previous change created a pointer to a
filter option in 'struct rev_info', so we can use that pointer here as a
start to simplifying some usage of object filters.

Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/pack-objects.c

@@ -3651,7 +3651,7 @@ static int pack_options_allow_reuse(void)
 
 static int get_object_list_from_bitmap(struct rev_info *revs)
 {
-	if (!(bitmap_git = prepare_bitmap_walk(revs, &filter_options, 0)))
+	if (!(bitmap_git = prepare_bitmap_walk(revs, &revs->filter, 0)))
 		return -1;
 
 	if (pack_options_allow_reuse() &&
@@ -3727,6 +3727,7 @@ static void get_object_list(int ac, const char **av)
 	repo_init_revisions(the_repository, &revs, NULL);
 	save_commit_buffer = 0;
 	setup_revisions(ac, av, &revs, &s_r_opt);
+	list_objects_filter_copy(&revs.filter, &filter_options);
 
 	/* make sure shallows are read */
 	is_repository_shallow(the_repository);
@@ -3777,7 +3778,7 @@ static void get_object_list(int ac, const char **av)
 
 	if (!fn_show_object)
 		fn_show_object = show_object;
-	traverse_commit_list_filtered(&filter_options, &revs,
+	traverse_commit_list_filtered(&revs.filter, &revs,
 				      show_commit, fn_show_object, NULL,
 				      NULL);