Such as RHEL5, where CLOEXEC, NONBLOCK flags are not present, use a
ifdef+define approach instead to make it build on all distros.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Vinson Lee <vlee@twitter.com>
Link: http://lkml.kernel.org/n/tip-pioazikk9d9oz5qdeor3eldu@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>