md/raid5: Cleanup cpu hotplug notifier

The raid456_cpu_notify() hotplug callback lacks handling of the
CPU_UP_CANCELED case. That means if CPU_UP_PREPARE fails, the scratch
buffer is leaked.

Add handling for CPU_UP_CANCELED[_FROZEN] hotplug notifier transitions
to free the scratch buffer.

CC: Shaohua Li <[e-mail]>
CC: [e-mail]
Signed-off-by: Anna-Maria Gleixner <[e-mail]>
Signed-off-by: Shaohua Li <[e-mail]>

drivers/md/raid5.c

···
 		break;
 	case CPU_DEAD:
 	case CPU_DEAD_FROZEN:
+	case CPU_UP_CANCELED:
+	case CPU_UP_CANCELED_FROZEN:
 		free_scratch_buffer(conf, per_cpu_ptr(conf->percpu, cpu));
 		break;
 	default: