perf evlist: Use PERF_EVENT_IOC_ID perf ioctl to read event id

perf evlist: Use PERF_EVENT_IOC_ID perf ioctl to read event id

Changing the way we retrieve the event ID. Instead of parsing out
the ID out of the read data, using the PERF_EVENT_IOC_ID ioctl.

Keeping the old way in place to support kernels without
PERF_EVENT_IOC_ID ioctl support.

This will be useful for retrieving the event ID for events
with PERF_FORMAT_GROUP read format set, where it's impossible
to get correct event id out of the read call data.

Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/n/tip-psgb4n7kte8e6tfenbe7nj2h@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>