powerpc/pseries: use slab context cpumask allocation in CPU hotplug init
Bugzilla: http://bugzilla.redhat.com/2022622
Brew: http://brewweb.engineering.redhat.com/brew/taskinfo?taskID=42500438
Upstream Status: https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git/
Conflicts: arch/powerpc/platforms/pseries/hotplug-cpu.c Changes of context
Tested: Sachin P Sant(IBM)
Signed-off-by: Gustavo Walbon gwalbon@redhat.com