[SCSI] correct attribute_container list usage

One of the changes in the attribute_container code in the scsi-misc tree
was to add a lock to protect the list of devices per container.  This,
unfortunately, leads to potential scheduling while atomic problems if
there's a sleep in the function called by a trigger.

The correct solution is to use the kernel klist infrastructure instead
which allows lockless traversal of a list.

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
diff --git a/include/linux/attribute_container.h b/include/linux/attribute_container.h
index ee83fe6..93bfb0b 100644
--- a/include/linux/attribute_container.h
+++ b/include/linux/attribute_container.h
@@ -11,12 +11,12 @@
 
 #include <linux/device.h>
 #include <linux/list.h>
+#include <linux/klist.h>
 #include <linux/spinlock.h>
 
 struct attribute_container {
 	struct list_head	node;
-	struct list_head	containers;
-	spinlock_t		containers_lock;
+	struct klist		containers;
 	struct class		*class;
 	struct class_device_attribute **attrs;
 	int (*match)(struct attribute_container *, struct device *);