net: mvneta: Add missing hotplug notifier transition

The mvneta_percpu_notifier() hotplug callback lacks handling of the
CPU_DOWN_FAILED case. That means, if CPU_DOWN_PREPARE failes, the
driver is not well configured on the CPU.

Add handling for CPU_DOWN_FAILED[_FROZEN] hotplug notifier transition
to setup the driver.

Cc: Thomas Petazzoni <[e-mail]>
Cc: [e-mail]
Signed-off-by: Anna-Maria Gleixner <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

drivers/net/ethernet/marvell/mvneta.c

···
 	switch (action) {
 	case CPU_ONLINE:
 	case CPU_ONLINE_FROZEN:
+	case CPU_DOWN_FAILED:
+	case CPU_DOWN_FAILED_FROZEN:
 		spin_lock(&pp->lock);
 		/* Configuring the driver for a new CPU while the
 		 * driver is stopping is racy, so just avoid it.