ap->port_task was not initialized if !CONFIG_ATA_SFF later triggering
lockdep warning.  Make sure it's initialized.
Reported by Larry Finger.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
 
 #ifdef CONFIG_ATA_SFF
        INIT_DELAYED_WORK(&ap->port_task, ata_pio_task);
+#else
+       INIT_DELAYED_WORK(&ap->port_task, NULL);
 #endif
        INIT_DELAYED_WORK(&ap->hotplug_task, ata_scsi_hotplug);
        INIT_WORK(&ap->scsi_rescan_task, ata_scsi_dev_rescan);