perf/x86: Vectorize cpuc->kfree_on_online

Make the cpuc->kfree_on_online a vector to accommodate
more than one entry and add the second entry to be
used by a later patch.

Signed-off-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Maria Dimakopoulou <maria.n.dimakopoulou@gmail.com>
Cc: bp@alien8.de
Cc: jolsa@redhat.com
Cc: kan.liang@intel.com
Link: http://lkml.kernel.org/r/1416251225-17721-3-git-send-email-eranian@google.com


Signed-off-by: Ingo Molnar <mingo@kernel.org>