[SCSI] scsi_debug: Convert to use root_device_register() and root_device_unregister()

This patch updates the scsi_debug virtual LLD to use
root_device_register() and root_device_unregister() from
include/linux/device.h instead of device_register() and
device_unregister() respectively within scsi_debug_init() and
scsi_debug_exit() This simply involved converting the static struct
device pseudo_primary into a pointer that is setup by the call to
root_device_register().

This patch also contains the correct IS_ERR() conditional check of
root_device_register() from within scsi_debug_init().

Thanks to Richard Sharpe and Dmitry Torokhov for their help with this
item.
Signed-off-by: Nicholas A. Bellinger <nab@linux-iscsi.org>
Acked-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

drivers/scsi/scsi_debug.c

@@ -3226,16 +3226,7 @@ static void do_remove_driverfs_files(void)
 	driver_remove_file(&sdebug_driverfs_driver, &driver_attr_add_host);
 }
 
-static void pseudo_0_release(struct device *dev)
-{
-	if (SCSI_DEBUG_OPT_NOISE & scsi_debug_opts)
-		printk(KERN_INFO "scsi_debug: pseudo_0_release() called\n");
-}
-
-static struct device pseudo_primary = {
-	.init_name	= "pseudo_0",
-	.release	= pseudo_0_release,
-};
+struct device *pseudo_primary;
 
 static int __init scsi_debug_init(void)
 {
@@ -3382,10 +3373,10 @@ static int __init scsi_debug_init(void)
 			map_region(0, 2);
 	}
 
-	ret = device_register(&pseudo_primary);
-	if (ret < 0) {
-		printk(KERN_WARNING "scsi_debug: device_register error: %d\n",
-			ret);
+	pseudo_primary = root_device_register("pseudo_0");
+	if (IS_ERR(pseudo_primary)) {
+		printk(KERN_WARNING "scsi_debug: root_device_register() error\n");
+		ret = PTR_ERR(pseudo_primary);
 		goto free_vm;
 	}
 	ret = bus_register(&pseudo_lld_bus);
@@ -3432,7 +3423,7 @@ static int __init scsi_debug_init(void)
 bus_unreg:
 	bus_unregister(&pseudo_lld_bus);
 dev_unreg:
-	device_unregister(&pseudo_primary);
+	root_device_unregister(pseudo_primary);
 free_vm:
 	if (map_storep)
 		vfree(map_storep);
@@ -3453,7 +3444,7 @@ static void __exit scsi_debug_exit(void)
 	do_remove_driverfs_files();
 	driver_unregister(&sdebug_driverfs_driver);
 	bus_unregister(&pseudo_lld_bus);
-	device_unregister(&pseudo_primary);
+	root_device_unregister(pseudo_primary);
 
 	if (dif_storep)
 		vfree(dif_storep);
@@ -3504,7 +3495,7 @@ static int sdebug_add_adapter(void)
         spin_unlock(&sdebug_host_list_lock);
 
         sdbg_host->dev.bus = &pseudo_lld_bus;
-        sdbg_host->dev.parent = &pseudo_primary;
+        sdbg_host->dev.parent = pseudo_primary;
         sdbg_host->dev.release = &sdebug_release_adapter;
         dev_set_name(&sdbg_host->dev, "adapter%d", scsi_debug_add_host);