[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/include/scsi/libiscsi.h b/include/scsi/libiscsi.h
index 7ffaed2..0289f57 100644
--- a/include/scsi/libiscsi.h
+++ b/include/scsi/libiscsi.h
@@ -36,6 +36,7 @@
 struct scsi_host_template;
 struct scsi_device;
 struct Scsi_Host;
+struct scsi_target;
 struct scsi_cmnd;
 struct socket;
 struct iscsi_transport;
@@ -350,6 +351,7 @@
 					  bool xmit_can_sleep);
 extern void iscsi_host_remove(struct Scsi_Host *shost);
 extern void iscsi_host_free(struct Scsi_Host *shost);
+extern int iscsi_target_alloc(struct scsi_target *starget);
 
 /*
  * session management