close file descriptor after trying perf_event_open
close file descriptor after trying perf_event_open

A resource leak in perf_skid

HPCToolkit/hpctoolkit,HPCToolkit/hpctoolkit,HPCToolkit/hpctoolkit,HPCToolkit/hpctoolkit,HPCToolkit/hpctoolkit,HPCToolkit/hpctoolkit