selftests/bpf: fix return value comparison for tests in test_libbpf.sh
The return value for each test in test_libbpf.sh is compared with
if (( $? == 0 )) ; then ...
This works well with bash, but not with dash, that /bin/sh is aliased to
on some systems (such as Ubuntu).
Let's replace this comparison by something that works on both shells.
Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Quentin Monnet