[SCSI] cxgb3i, iser, iscsi_tcp: set target can queue

Set target can queue limit to the number of preallocated
session tasks we have.

This along with the cxgb3i can_queue patch will fix a throughput
problem where it could only queue one LU worth of data at a time.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
diff --git a/drivers/scsi/iscsi_tcp.c b/drivers/scsi/iscsi_tcp.c
index f97fc7e..b7c092d 100644
--- a/drivers/scsi/iscsi_tcp.c
+++ b/drivers/scsi/iscsi_tcp.c
@@ -851,6 +851,7 @@
 	.use_clustering         = DISABLE_CLUSTERING,
 	.slave_alloc            = iscsi_sw_tcp_slave_alloc,
 	.slave_configure        = iscsi_sw_tcp_slave_configure,
+	.target_alloc		= iscsi_target_alloc,
 	.proc_name		= "iscsi_tcp",
 	.this_id		= -1,
 };