Since commit 1cf4f629 ("cpu/hotplug: Move online calls to
hotplugged cpu") the CPU_ONLINE and CPU_DOWN_PREPARE notifiers are
always run on the hot plugged CPU, and as of commit 3b9d6da6
("cpu/hotplug: Fix rollback during error-out in __cpu_disable()") the
CPU_DOWN_FAILED notifier also runs on the hot plugged CPU. This patch
converts the SMP functional calls into direct calls.

smp_function_call_single() executes the function with interrupts
disabled. This calling convention is not preserved, because
tick_broadcast_enable() and tick_braodcast_disable() handle
interrupts themselves.
Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>