pata_legacy: fix no device fail path

When pata_legacy can't detect any device, it unregisters the
platform_device and fails detection.  However, it forgets to detach
ata host triggering weird failures as the host later gets freed by
devres while still attached.  Fix it.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

drivers/ata/pata_legacy.c

@@ -1032,6 +1032,7 @@ static __init int legacy_init_one(struct legacy_probe *probe)
 			return 0;
 		}
 	}
+	ata_host_detach(host);
 fail:
 	platform_device_unregister(pdev);
 	return ret;