perf: Optimize ctx_sched_out()

Oleg noted that ctx_sched_out() disables the PMU even though it might
not actually do something, avoid needless PMU-disabling.

Reported-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20110409192141.665385503@chello.nl
Signed-off-by: Ingo Molnar <mingo@elte.hu>
1 file changed