net: mvneta: fix locking in mvneta_cpu_online()

When port is stopped, unlock before returning

Fixes: 413f027 ("net: protect NAPI enablement with netdev_lock()")
Signed-off-by: Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20250121005002.3938236-1-harshit.m.mogalapalli@oracle.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/marvell/mvneta.c

@@ -4432,6 +4432,7 @@ static int mvneta_cpu_online(unsigned int cpu, struct hlist_node *node)
 	 */
 	if (pp->is_stopped) {
 		spin_unlock(&pp->lock);
+		netdev_unlock(port->napi.dev);
 		return 0;
 	}
 	netif_tx_stop_all_queues(pp->dev);