[S390] replace lock_cpu_hotplug with get_online_cpus

Git commit 86ef5c9a8edd78e6bf92879f32329d89b2d55b5a forgot a few
lock_cpu_hotplug/unlock_cpu_hotplug pairs in arch/s390/kernel/smp.c

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
1 file changed