builtin/for-each-ref: free filter and UNLEAK sorting.

sorting might be a list allocated in ref_default_sorting() (in this case
it's a fixed single item list, which has nevertheless been xcalloc'd),
or it might be a list allocated in parse_opt_ref_sorting(). In either
case we could free these lists - but instead we UNLEAK as we're at the
end of cmd_for_each_ref. (There's no existing implementation of
clear_ref_sorting(), and writing a loop to free the list seems more
trouble than it's worth.)

filter.with_commit/no_commit are populated via
OPT_CONTAINS/OPT_NO_CONTAINS, both of which create new entries via
parse_opt_commits(), and also need to be free'd or UNLEAK'd. Because
free_commit_list() already exists, we choose to use that over an UNLEAK.

LSAN output from t0041:

Direct leak of 16 byte(s) in 1 object(s) allocated from:
    #0 0x49a9d2 in calloc ../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:154:3
    #1 0x9ac252 in xcalloc wrapper.c:140:8
    #2 0x8a4a55 in ref_default_sorting ref-filter.c:2486:32
    #3 0x56c6b1 in cmd_for_each_ref builtin/for-each-ref.c:72:13
    #4 0x4cd91d in run_builtin git.c:467:11
    #5 0x4cb5f3 in handle_builtin git.c:719:3
    #6 0x4ccf47 in run_argv git.c:808:4
    #7 0x4caf49 in cmd_main git.c:939:19
    #8 0x69dabe in main common-main.c:52:11
    #9 0x7f2bdc570349 in __libc_start_main (/lib64/libc.so.6+0x24349)

Direct leak of 16 byte(s) in 1 object(s) allocated from:
    #0 0x49a85d in malloc ../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:145:3
    #1 0x9abf54 in do_xmalloc wrapper.c:41:8
    #2 0x9abf2a in xmalloc wrapper.c:62:9
    #3 0x717486 in commit_list_insert commit.c:540:33
    #4 0x8644cf in parse_opt_commits parse-options-cb.c:98:2
    #5 0x869bb5 in get_value parse-options.c:181:11
    #6 0x8677dc in parse_long_opt parse-options.c:378:10
    #7 0x8659bd in parse_options_step parse-options.c:817:11
    #8 0x867fcd in parse_options parse-options.c:870:10
    #9 0x56c62b in cmd_for_each_ref builtin/for-each-ref.c:59:2
    #10 0x4cd91d in run_builtin git.c:467:11
    #11 0x4cb5f3 in handle_builtin git.c:719:3
    #12 0x4ccf47 in run_argv git.c:808:4
    #13 0x4caf49 in cmd_main git.c:939:19
    #14 0x69dabe in main common-main.c:52:11
    #15 0x7f2bdc570349 in __libc_start_main (/lib64/libc.so.6+0x24349)

Signed-off-by: Andrzej Hunt <ajrhunt@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/for-each-ref.c

@@ -83,5 +83,8 @@ int cmd_for_each_ref(int argc, const char **argv, const char *prefix)
 	for (i = 0; i < maxcount; i++)
 		show_ref_array_item(array.items[i], &format);
 	ref_array_clear(&array);
+	free_commit_list(filter.with_commit);
+	free_commit_list(filter.no_commit);
+	UNLEAK(sorting);
 	return 0;
 }