KVM: Tune hotplug/suspend IPIs

The hotplug IPIs can be called from the cpu on which we are currently
running on, so use on_cpu().  Similarly, drop on_each_cpu() for the
suspend/resume callbacks, as we're in atomic context here and only one
cpu is up anyway.
Signed-off-by: Avi Kivity <avi@qumranet.com>

drivers/kvm/kvm_main.c

@@ -3110,13 +3110,13 @@ static void kvm_exit_debug(void)
 
 static int kvm_suspend(struct sys_device *dev, pm_message_t state)
 {
-	on_each_cpu(hardware_disable, NULL, 0, 0);
+	hardware_disable(NULL);
 	return 0;
 }
 
 static int kvm_resume(struct sys_device *dev)
 {
-	on_each_cpu(hardware_disable, NULL, 0, 0);
+	hardware_enable(NULL);
 	return 0;
 }