Merge branch 'Fix resource leaks in test_maps'

Hou Tao says:

====================

From: Hou Tao <houtao1@huawei.com>

Hi,

It is just a tiny patch set aims to fix the resource leaks in test_maps
after test case succeeds or is skipped. And these leaks are spotted by
using address sanitizer and checking the content of /proc/$pid/fd.

Please see indiviual patch for more details.

Change Log:
v2:
 * Add the missing header file unistd.h for close() (From kernel-patches/bpf)
   The reason Why I miss that is that -Werror is removed from Makefile
   when enabling clang address sanitizer.

v1:
 * https://lore.kernel.org/bpf/20220921025855.115463-1-houtao@huaweicloud.com/T/
====================

Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>