"perf is not linked with libtraceevent" warning

[lucaceresoli]

During the uprobes lab based on perf, this warning is shown:

perf is not linked with libtraceevent, to use the new probe you can use tracefs:

        cd /sys/kernel/tracing/
        echo 1 > events/probe_crc_random/main_L35/enable
        echo 1 > tracing_on
        cat trace_pipe
        Before removing the probe, echo 0 > events/probe_crc_random/main_L35/enable

It does not prevent from completing the lab, it is just an annoyance but it would be nice to fix.