[SCSI] libiscsi: make can_queue configurable

This patch allows us to set can_queue and cmds_per_lun from userspace
when we create the session/host. From there we can set it on a per
target basis. The patch fully converts iscsi_tcp, but only hooks
up ib_iser for cmd_per_lun since it currently has a lots of preallocations
based on can_queue.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Cc: Roland Dreier <rdreier@cisco.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

drivers/scsi/scsi_transport_iscsi.c

@@ -814,6 +814,8 @@ iscsi_if_create_session(struct iscsi_internal *priv, struct iscsi_uevent *ev)
 	uint32_t hostno;
 
 	session = transport->create_session(transport, &priv->t,
+					    ev->u.c_session.cmds_max,
+					    ev->u.c_session.queue_depth,
 					    ev->u.c_session.initial_cmdsn,
 					    &hostno);
 	if (!session)