uled on CPU 1
 |         - perf_event_exit_task is called
 |         - task_ctx_sched_out unsets cpuctx->task_ctx on CPU 1
 |         - put_ctx destroys the context
 |
 | - another call of perf_rotate_context on CPU 0 will use invalid
 |   task_ctx pointer, and eventualy panic.
 |

Cure this the simplest possibly way by partially reverting the
jump_label optimization for the sched_out case.

Reported-and-tested-by: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: <stable@kernel.org> # .37+
LKML-Reference: <1301520405.4859.213.camel@twins>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
í