[PATCH bpf] selftests/bpf: fix error return code in run_getsockopt_test()

[Wang Hai]

Fix to return a negative error code from the error handling
case instead of 0, as done elsewhere in this function.

Fixes: 65b4414a05eb ("selftests/bpf: add sockopt test that exercises 
BPF_F_ALLOW_MULTI")
Reported-by: Hulk Robot <hul...@huawei.com>
Signed-off-by: Wang Hai <wangha...@huawei.com>
---
 tools/testing/selftests/bpf/prog_tests/sockopt_multi.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/bpf/prog_tests/sockopt_multi.c 
b/tools/testing/selftests/bpf/prog_tests/sockopt_multi.c
index 29188d6f5c8d..51fac975b316 100644
--- a/tools/testing/selftests/bpf/prog_tests/sockopt_multi.c
+++ b/tools/testing/selftests/bpf/prog_tests/sockopt_multi.c
@@ -138,7 +138,8 @@ static int run_getsockopt_test(struct bpf_object *obj, int 
cg_parent,
         */
 
        buf = 0x40;
-       if (setsockopt(sock_fd, SOL_IP, IP_TOS, &buf, 1) < 0) {
+       err = setsockopt(sock_fd, SOL_IP, IP_TOS, &buf, 1);
+       if (err < 0) {
                log_err("Failed to call setsockopt(IP_TOS)");
                goto detach;
        }
-- 
2.17.1