[ Upstream commit f48ad69097fe79d1de13c4d8fef556d4c11c5e68 ] Make sure to use pclose() to properly close the pipe opened by popen(). Fixes: 81f77fd0deeb ("bpf: add selftest for stackmap with BPF_F_STACK_BUILD_ID") Signed-off-by: Andrea Righi <andrea.righi@canonical.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Shuah Khan <skhan@linuxfoundation.org> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20211026143409.42666-1-andrea.righi@canonical.com Signed-off-by: Sasha Levin <sashal@kernel.org>