[PATCH bpf] bpf: minor fix to selftest test_stacktrace_build_id()

[Song Liu]

1. remove useless parameter list to ./urandom_read
2. add missing "\n" to the end of an error message

Fixes: 81f77fd0deeb ("bpf: add selftest for stackmap with BPF_F_STACK_BUILD_ID")
Cc: Alexei Starovoitov <a...@kernel.org>
Cc: Daniel Borkmann <dan...@iogearbox.net>
Signed-off-by: Song Liu <songliubrav...@fb.com>
---
 tools/testing/selftests/bpf/test_progs.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/bpf/test_progs.c 
b/tools/testing/selftests/bpf/test_progs.c
index faadbe2..4123d0a 100644
--- a/tools/testing/selftests/bpf/test_progs.c
+++ b/tools/testing/selftests/bpf/test_progs.c
@@ -1108,7 +1108,7 @@ static void test_stacktrace_build_id(void)
 
        assert(system("dd if=/dev/urandom of=/dev/zero count=4 2> /dev/null")
               == 0);
-       assert(system("./urandom_read if=/dev/urandom of=/dev/zero count=4 2> 
/dev/null") == 0);
+       assert(system("./urandom_read") == 0);
        /* disable stack trace collection */
        key = 0;
        val = 1;
@@ -1158,7 +1158,7 @@ static void test_stacktrace_build_id(void)
        } while (bpf_map_get_next_key(stackmap_fd, &previous_key, &key) == 0);
 
        CHECK(build_id_matches < 1, "build id match",
-             "Didn't find expected build ID from the map");
+             "Didn't find expected build ID from the map\n");
 
 disable_pmu:
        ioctl(pmu_fd, PERF_EVENT_IOC_DISABLE);
-- 
2.9.5