On ARM32 building it report following error when we build with libbabeltrace: util/data-convert-bt.c: In function 'add_bpf_output_values': util/data-convert-bt.c:440:3: error: format '%lu' expects argument of type 'long unsigned int', but argument 5 has type 'unsigned int' [-Werror=format] cc1: all warnings being treated as errors Fix it by changing %lu to %zu. Signed-off-by: Wang Nan <wangnan0@huawei.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Zefan Li <lizefan@huawei.com> Cc: pi3orama@163.com Fixes: 6122d57e9f7c ("perf data: Support converting data from bpf_perf_event_output()") Link: http://lkml.kernel.org/r/1475035126-146587-1-git-send-email-wangnan0@huawei.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>