libata: clear drvdata in ata_host_release(), take#2

Clearing drvdata in ->remove_one causes NULL pointer deference.  Clear
drvdata only in ata_host_release() after all resources are freed.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index c8d44a7..17ad152 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -5680,6 +5680,8 @@
 
 	if (host->ops->host_stop)
 		host->ops->host_stop(host);
+
+	dev_set_drvdata(gendev, NULL);
 }
 
 /**
@@ -5902,7 +5904,6 @@
 
  err_out:
 	devres_release_group(dev, ata_device_add);
-	dev_set_drvdata(dev, NULL);
 	VPRINTK("EXIT, returning %d\n", rc);
 	return 0;
 }
diff --git a/drivers/ata/pata_cs5520.c b/drivers/ata/pata_cs5520.c
index c1334c6..8ff2d58 100644
--- a/drivers/ata/pata_cs5520.c
+++ b/drivers/ata/pata_cs5520.c
@@ -306,7 +306,6 @@
 	struct ata_host *host = dev_get_drvdata(dev);
 
 	ata_host_detach(host);
-	dev_set_drvdata(dev, NULL);
 }
 
 /**
diff --git a/drivers/ata/pata_isapnp.c b/drivers/ata/pata_isapnp.c
index d5f2e85..1a61cc8 100644
--- a/drivers/ata/pata_isapnp.c
+++ b/drivers/ata/pata_isapnp.c
@@ -128,7 +128,6 @@
 	struct ata_host *host = dev_get_drvdata(dev);
 
 	ata_host_detach(host);
-	dev_set_drvdata(dev, NULL);
 }
 
 static struct pnp_device_id isapnp_devices[] = {
diff --git a/drivers/ata/pata_platform.c b/drivers/ata/pata_platform.c
index 02ea95f..4b82a54 100644
--- a/drivers/ata/pata_platform.c
+++ b/drivers/ata/pata_platform.c
@@ -228,7 +228,6 @@
 	struct ata_host *host = dev_get_drvdata(dev);
 
 	ata_host_detach(host);
-	dev_set_drvdata(dev, NULL);
 
 	return 0;
 }