perf tools: Fix CLOEXEC probe for perf_event_paranoid == 2

With /proc/sys/kernel/perf_event_paranoid set to 2, the probe of
PERF_FLAG_FD_CLOEXEC would fail.  Fix by excluding kernel profiling from
the probe event.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1407855871-15024-2-git-send-email-adrian.hunter@intel.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/cloexec.c

@@ -11,6 +11,7 @@ static int perf_flag_probe(void)
 	struct perf_event_attr attr = {
 		.type = PERF_TYPE_SOFTWARE,
 		.config = PERF_COUNT_SW_CPU_CLOCK,
+		.exclude_kernel = 1,
 	};
 	int fd;
 	int err;