[SCSI] iscsi class: fix slab corruption during restart

The transport class recv mempools are causing slab corruption.
We could hack around netlink's lack of mempool support like dm,
but it is just too ulgy (dm's hack is ugly enough :) when you need
to support broadcast.

This patch removes the recv pools. We have not used them even when
we were allocting 20 MB per session and the system only had 64 MBs.
And we have no pools on the send side and have been ok there. When
Peter's work gets merged we can use that since the network guys
are in favor of that approach and are not going to add mempools
everywhere.
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

include/scsi/scsi_transport_iscsi.h

@@ -29,7 +29,6 @@
 struct scsi_transport_template;
 struct iscsi_transport;
 struct Scsi_Host;
-struct mempool_zone;
 struct iscsi_cls_conn;
 struct iscsi_conn;
 struct iscsi_cmd_task;
@@ -157,9 +156,6 @@ struct iscsi_cls_conn {
 
 	int active;			/* must be accessed with the connlock */
 	struct device dev;		/* sysfs transport/container device */
-	struct mempool_zone *z_error;
-	struct mempool_zone *z_pdu;
-	struct list_head freequeue;
 };
 
 #define iscsi_dev_to_conn(_dev) \