[SCSI] libiscsi, iscsi_tcp, iser: add session cmds array accessor

Currently to get a ctask from the session cmd array, you have to
know to use the itt modifier. To make this easier on LLDs and
so in the future we can easilly kill the session array and use
the host shared map instead, this patch adds a nice wrapper
to strip the itt into a session->cmds index and return a ctask.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
diff --git a/drivers/infiniband/ulp/iser/iscsi_iser.c b/drivers/infiniband/ulp/iser/iscsi_iser.c
index 8a1bfb7..7b14688 100644
--- a/drivers/infiniband/ulp/iser/iscsi_iser.c
+++ b/drivers/infiniband/ulp/iser/iscsi_iser.c
@@ -98,7 +98,6 @@
 		struct iscsi_hdr *hdr, char *rx_data, int rx_data_len)
 {
 	int rc = 0;
-	uint32_t ret_itt;
 	int datalen;
 	int ahslen;
 
@@ -114,12 +113,7 @@
 	/* read AHS */
 	ahslen = hdr->hlength * 4;
 
-	/* verify itt (itt encoding: age+cid+itt) */
-	rc = iscsi_verify_itt(conn, hdr, &ret_itt);
-
-	if (!rc)
-		rc = iscsi_complete_pdu(conn, hdr, rx_data, rx_data_len);
-
+	rc = iscsi_complete_pdu(conn, hdr, rx_data, rx_data_len);
 	if (rc && rc != ISCSI_ERR_NO_SCSI_CMD)
 		goto error;