perf evlist: Fix event ID retrieval for group format read case

perf evlist: Fix event ID retrieval for group format read case

We need to fail the event ID retrieval in case both following conditions
are true:

  - we are on kernel with no PERF_EVENT_IOC_ID support
  - PERF_FORMAT_GROUP read format is set

The PERF_FORMAT_GROUP read format bit is the killer for retrieving event
ID out of the read syscall, because we have no guarantee of the event
placement within leader kernel sibling list.

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-e93pgyj20rqx48qzw10vj4r4@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>