[PATCH] selftests/bpf: don't close(-1) in serial_test_fexit_stress()

[Ma Ke]

Guard close() with extra link_fd[i] >= 0 and fexit_fd[i] >= 0
check to prevent close(-1).

Signed-off-by: Ma Ke <mak...@iscas.ac.cn>
---
 tools/testing/selftests/bpf/prog_tests/fexit_stress.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/bpf/prog_tests/fexit_stress.c 
b/tools/testing/selftests/bpf/prog_tests/fexit_stress.c
index 596536def43d..94ff1d9fc9e4 100644
--- a/tools/testing/selftests/bpf/prog_tests/fexit_stress.c
+++ b/tools/testing/selftests/bpf/prog_tests/fexit_stress.c
@@ -50,9 +50,9 @@ void serial_test_fexit_stress(void)
 
 out:
        for (i = 0; i < bpf_max_tramp_links; i++) {
-               if (link_fd[i])
+               if (link_fd[i] >= 0)
                        close(link_fd[i]);
-               if (fexit_fd[i])
+               if (fexit_fd[i] >= 0)
                        close(fexit_fd[i]);
        }
        free(fd);
-- 
2.25.1